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Identity Abuse Through Trusted Communication Channels

20 August 2026 at 12:00

Unit 42 details how attackers exploit enterprise collaboration tools for identity phishing and credential theft. Discover key defense strategies.

The post Identity Abuse Through Trusted Communication Channels appeared first on Unit 42.

Inside the Modern SOC: The Identity Front Door

8 August 2026 at 01:00

Identity-based attacks drive 90% of incidents. Learn how modern attackers exploit identities and what SOC leaders can do to respond.

The post Inside the Modern SOC: The Identity Front Door appeared first on Unit 42.

CrashStealer, a new infostealer for macOS: how it works and how to stay safe | Kaspersky official blog

3 August 2026 at 16:01

Mac users have historically trusted their operating system to keep them safe. That peace of mind mostly comes from Apple’s strict control over its ecosystem, and the fact that macOS has historically faced fewer mass attacks than Windows. However, that doesn’t mean Macs are invulnerable: threats do exist, and new ones emerge all the time. Over just the past few weeks, security researchers have published reports on at least two new campaigns that target Apple devices.

The malware used in one of the campaigns has been dubbed CrashStealer, while the other is known as ClickLock. Both rely on different tricks to force users into entering their Mac password, which attackers then use to steal account credentials, crypto assets, documents, and much more. In today’s post, we take a close look at how CrashStealer operates — and how to avoid falling victim to it.

A videoconferencing app with CrashStealer inside

It was back in May 2026 that researchers spotted the first signs this malware was being developed, and by early July, they caught it operating in the wild. The malware earned its name because of its core mechanism: it disguises itself as the macOS built-in crash reporting tool (CrashReporter) while functioning as an infostealer designed to hijack sensitive data.

Researchers managed to trace one of the websites users visited to download the malware. The site poses as a legitimate platform for distributing the video conferencing tool Werkbit.

A website that distributes CrashStealer under the guise of the Werkbit app

According to researchers, this is the site victims used to download Werkbit, which secretly contained the CrashStealer malware loader. Source

However, you can’t just visit the site and download the software. Before downloading, visitors are asked to enter a special meeting PIN. This setup likely allows the attackers to limit the distribution scope by targeting only specific, pre-selected victims. Exactly how the cybercriminals choose their targets and deliver the PIN remains unknown.

The “lucky” users with a code end up installing the initial malicious payload — named Werkbit Setup. Interestingly, it carries a valid Apple developer certificate and has successfully passed Apple’s notarization process — meaning it cleared the automated prescan for malicious code. As a result, the attackers manage to bypass the operating system’s built-in Gatekeeper defense. This allows the payload to launch without triggering the usual untrusted software warnings.

Signed and notarized Werkbit Setup installer

The Werkbit Setup installer is signed with a valid Apple developer certificate and has passed notarization. Source

Once launched, Werkbit Setup first reaches out to GitHub. Researchers believe using this popular platform helps attackers blend in by making these initial network requests look far less suspicious to security tools. After retrieving instructions from a GitHub repository, the program connects directly to the attackers’ server to fetch CrashStealer itself.

The loader then saves the malware to a temporary macOS folder, launches it, and wipes most of the intermediate setup files. As a result, a fully functional infostealer is up and running within seconds of Werkbit Setup starting. By the way, the user never gets any videoconferencing app.

How CrashStealer works

Unlike the Werkbit Setup loader, the CrashStealer malware itself isn’t signed with an Apple developer certificate. To keep users from suspecting anything, the malware disguises itself as the built-in macOS crash reporting tool, CrashReporter, by using the exact same name, app identifier, and a similar icon.

Once launched, CrashStealer completes a sequence of steps to gain access to sensitive data, establish persistence in the system, and cover its tracks:

  1. Remove metadata — including the attribute that flags the app as an internet download.
  2. Display a fake system prompt asking for the user’s macOS password.
  3. Use the previously captured credentials to gain access to Keychain, the built-in macOS password manager.
  4. Check the computer for installed security tools and malware analysis software.
  5. Collect saved browser passwords, cookies, Keychain contents, and data from other password managers and crypto wallets.
  6. Encrypt the data it stole and prepare it for forwarding to the attackers’ server.
  7. Create a copy of itself and establish persistence to launch automatically every time macOS boots.
  8. Delete temporary files and other installation traces to make detection much harder.

Step two deserves a closer look. The password prompt that the user sees looks extremely convincing. What’s more, the malware immediately verifies whether the credentials are correct: if you make a typo and enter an invalid password, CrashStealer will pop the window right back up to ask you again.

Fake macOS password prompt

Once launched, CrashStealer displays a pop-up that mimics the standard macOS password request. Source

What data is CrashStealer after?

CrashStealer’s hit list is massive. First and foremost, its operators target Keychain: the built-in macOS password manager where the system stores account credentials, cryptographic keys, certificates, tokens, and more.

Users of third-party password managers aren’t safe either: the malware steals data from 14 of these services, including 1Password, Bitwarden, LastPass, Dashlane, Keeper, KeePassXC, NordPass, Enpass, and RoboForm.

In addition, the malware collects all credentials and cookies stored in Chromium-based browsers — Chrome, Brave, Edge, Opera, Opera GX, Vivaldi, Chromium, and NAVER Whale — as well as Firefox. The attackers clearly have a strong interest in crypto assets: CrashStealer specifically targets data from 80 different crypto wallet extensions, including MetaMask, Phantom, Coinbase Wallet, Trust Wallet, Rabby, Exodus, Keplr, and Solflare.

Finally, the malware scans the Documents and Downloads folders to pick files that might be of interest to the cybercriminals. CrashStealer encrypts all the stolen data with the AES-256-GCM algorithm, ZIP’s it up, and sends it to the attackers’ server.

How to protect your device

The spike in attacks on macOS is a clear wake-up call: Apple users need to get proactive about their security. We recommend:

  • Researching apps online before installing them
  • Sticking to utilities from official app stores whenever possible
  • Using a reliable security solution that blocks malicious websites and stops malware activity on your device
  • Keeping all your credentials and banking details in a secure password manager. One option is Kaspersky Password Manager— which, notably, wasn’t listed among the apps targeted by CrashStealer

Kaspersky security solutions detect the malware described in this post and assigns to it the verdicts HEUR:Trojan-Downloader.OSX.Agent.gen and HEUR:Trojan-PSW.OSX.Agent.gen.

CaptiveCrunch: Midnight Blizzard targets travelers worldwide for malware delivery and credential theft

Since early May 2026, Microsoft Threat Intelligence has observed Storm-2945, a sub-cluster of Midnight Blizzard, conducting widespread but targeted traffic manipulation attacks involving hospitality sector networks served by captive portals worldwide. Despite some tactic, technique, and procedure (TTP) similarities to the Forest Blizzard DNS hijacking operation that we publicly disclosed in April 2026, we attribute this campaign, which we call CaptiveCrunch, to Storm-2945. As reported by ReliaQuest on July 23, a portion of this activity leverages doppelganger domains mimicking Microsoft online services to conduct follow-on adversary-in-the-middle (AitM) phishing operations that abuse the device code authentication flow in Microsoft Entra ID. Microsoft Threat Intelligence has also identified active traffic manipulation attacks leading to the delivery of malware on impacted systems. Microsoft has observed Storm-2945 leveraging AI to support a significant portion of these operations.

Today, we are sharing our findings on these ongoing intrusions to raise awareness of this threat and enable customers to protect their devices, especially while traveling. We provide our assessment of Storm-2945’s relationship to Midnight Blizzard and analysis of the CaptiveCrunch campaign, detailing the malware and tradecraft used in these operations. We also provide mitigation, detection, and hunting guidance to help organizations identify and defend against Storm-2945 and related activity.

Microsoft Threat Intelligence would like to thank our partners at Anthropic and OpenAI for their collaboration and support during this investigation.

The CaptiveCrunch campaign

Since February 2026, Storm-2945 has conducted AI-augmented operations including targeted device code and OAuth code phishing campaigns leading to Entra device registration and subsequent data collection from Microsoft 365. Since early May 2026, Microsoft Threat Intelligence has observed Storm-2945 manipulating DNS and HTTP traffic from networks served by captive portals to redirect user traffic through actor-controlled infrastructure. Although our investigation into the initial compromise vector for the captive portal networks is ongoing, we have observed notable commonalities in the equipment and management systems used across multiple affected networks. These similarities suggest that the activity might not be limited to isolated compromises of individual venues and could reflect access to shared services within portions of the captive portal ecosystem.

Diagram depicting an overview of the CaptiveCrunch campaign attack flow
Figure 1. Overview of the CaptiveCrunch attack flow

As part of the CaptiveCrunch campaign, Storm-2945 has leveraged their AitM position to redirect users through actor-controlled phishing infrastructure and has also delivered malware purporting to be browser or operating system updates in response to automated connectivity checks issued by users’ browsers. Multiple variants have been delivered, including fully-featured Windows remote access trojans (RAT) in compiled Golang, with functionality to conduct system enumeration, collect files and keystrokes, steal credentials and session tokens, conduct audio and video surveillance, monitor for removable media, and provide the threat actor a remote shell on infected systems.  

The threat actor infrastructure leverages a variety of ClickFix techniques to elicit the user into downloading and executing the malware:

A Windows Driver Repair Utility interface, with instructions for manually repairing a failed automated driver repair, including steps to run a verification script via Windows Terminal.
Figure 2. ClickFix prompt with manual user instructions
A Google web page claiming the verification check failed with additional manual instructions for the user to follow.
Figure 3. ClickFix prompt with additional user instructions after verification failure

In addition to variants of malware targeting Windows systems, Microsoft Threat Intelligence is also aware of indications that the threat actor might be targeting Android devices with similar techniques as the ClickFix landings also include instructions for Android devices to download and install an APK file.

To date, Microsoft has identified widespread compromise of Wi-Fi networks at hospitality-related organizations and other networks serviced by captive portal equipment in several countries. ReliaQuest has identified this activity not only at hotels, but also conference centers and other shared venues, and assesses that the goal of this activity is to access the accounts of corporate travelers.

Storm-2945 and Midnight Blizzard

Microsoft Threat Intelligence assesses that Storm-2945 is an operational sub-cluster of Midnight Blizzard based on distinctive technical and operational overlaps. These include technical similarities to Storm-2372, a Midnight Blizzard initial access operations sub-cluster, also notable for their device code and OAuth code phishing operations tracked throughout 2025, Microsoft Graph-based email exfiltration, social engineering delivered via commercial messaging apps, and significant similarities in victimology.

Midnight Blizzard is a Russia-based threat actor attributed by the US and UK governments to the Foreign Intelligence Service of the Russian Federation, also known as the SVR. This threat actor is known to primarily target governments, diplomatic entities, non-governmental organizations (NGOs), and information technology (IT) service providers, primarily in the US and Europe. Midnight Blizzard is consistent and persistent in their operational targeting, and their objectives rarely change. Their focus is to collect intelligence through longstanding and dedicated espionage in support of Russian foreign policy interests.

Midnight Blizzard operations often involve compromise of valid accounts and, in some highly targeted cases, advanced techniques to compromise authentication mechanisms within an organization to expand access and evade detection. They utilize diverse initial access methods, and Midnight Blizzard is also adept at identifying and abusing OAuth applications to move laterally across cloud environments and for post-compromise activity, such as email collection.

CaptiveCrunch tradecraft and tooling

CornFlake: Remote access and infostealer implant

CornFlake is a full-featured Windows RAT written in Go that serves as Storm-2945’s primary persistent implant. Microsoft has observed the threat actor rapidly iterating on this malware layer, which features customizable capabilities from the social engineering user interface and data collection capabilities to anti-detection and evasion techniques.

On initial execution, CornFlake operates in dropper mode: it displays a convincing fake progress window designed to occupy the victim’s attention while the binary copies itself to %APPDATA%\svchost32\svchost32.exe and establishes persistence.

Fake window options configurable by the threat actor at build time:

  • winupdate — A Windows Update screen displaying “Working on updates… Don’t turn off your computer”
  • defender — A Windows Security virus scan
  • directx — A DirectX End-User Runtime Web Installer
  • vcredist — A Microsoft Visual C++ 2015-2022 Redistributable installer
  • sysopt — A disk optimization utility
  • netfix — A Windows Network Diagnostics tool
  • browser — A browser update prompt
  • pdfview — A document viewer installer
A false update window claiming the updates are 3 percent downloaded.
Figure 4. False update window

CornFlake registers as a Windows service named svchost32 with the display name “Cloud Sync Service and description “Synchronizes files with the cloud storage provider”, deliberately mimicking the legitimate svchost.exe process. It establishes redundant persistence mechanisms: Windows service registrations, Registry Run keys, named scheduled tasks, and a persistence watchdog routine that runs continuously to restore any persistence mechanism that is removed by defenders or endpoint protection.

For command and control (C2), CornFlake performs an Elliptic Curve Diffie-Hellman (ECDH) P-256 ephemeral key exchange with the C2 server, derives a session key via SHA-256, and communicates over a custom JSON protocol framed within the encrypted channel. This provides an encrypted channel to the C2 server, with each C2 session using a unique ephemeral key, making decryption of captured traffic impossible without the session-specific private key. The runtime configuration file sync.dat supports hot reconfiguration of C2 servers, watched directories, file targeting patterns, and Transport Layer Security (TLS) settings without requiring redeployment.

Once established on a victim system, CornFlake provides the operator with a comprehensive collection toolkit, gated by configuration flags that allow selective activation post-deployment:

CapabilityDescription
KeyloggingRaw input API-based keylogger capturing all keystrokes, including password fields
Clipboard monitoringCaptures clipboard changes with SHA-256 deduplication and records the active window title at time of capture
Screenshot captureIdle-triggered and on-demand screenshots with configurable idle threshold
Audio surveillanceWindows Audio Session API (WASAPI)-based microphone capture, encoded as WAV files
Video surveillanceMedia Foundation-based webcam capture, encoded as JPEG
Browser credential theftChromeKatz-derived module supporting live cookie extraction from process memory (Chromium browsers) and stored password extraction from on-disk databases, including Chrome App-Bound Encryption (ABE) bypass and Firefox NSS/SDR decryption
File exfiltrationTargets files based on file extensions with real-time file system monitoring and an upload throttle (1,000 files or 500 MB per cycle). File extensions are categorized as Documents, Archives, Images, Code, Data, Emails, and Keys
USB drive monitoringDetects and scans removable media when inserted
Security posture sweepCollects 18 categories of host intelligence including installed software, antivirus (AV)/endpoint detection and response (EDR) products, Defender exclusions, User Account Control (UAC) level, Remote Desktop Protocol (RDP) history, Office most recently used (MRU) files, and credential hints
Remote shellArbitrary command execution via cmd.exe or PowerShell (with -NoP flag to suppress profile-based detection)

CornFlake also exposes a localhost HTTP API server (/upload, /reload, /status) that transforms the RAT into a modular platform: companion or next-stage payloads such as ChocoShell could task file exfiltration, trigger configuration hot reloads or check C2 connectivity using the pre-established secure C2 channel for communication.

ChocoShell: PowerShell infostealer

ChocoShell is the campaign’s Powershell-based infostealer, delivered and executed entirely in-memory. Its primary objective is the high-volume theft of browser session cookies, saved passwords, Microsoft 365 Single Sign-On (SSO) tokens, and Wi-Fi credentials from compromised systems. Where CornFlake provides the operator with a persistent, long-running foothold on the device, ChocoShell is designed to extract the most operationally valuable credentials, giving the operator access to victim cloud environments.

The ChocoShell script was authored with full developer comments that reveal the operator’s intent behind each code decision, including explicit references to Microsoft detection signatures and the reasoning behind specific evasion choices. The consistent coding standard and descriptive commentary suggest the author might have leveraged AI-assisted code generation.

Defense evasion. Upon execution, ChocoShell beacons to a hardcoded C2 server at 213.145.86[.]112 and implements several evasion techniques in sequence. It disables the Antimalware Scan Interface (AMSI) via .NET reflection to prevent ScriptBlock scanning and evades Microsoft behavioral detection that triggers on suspicious PowerShell web request cmdlets. A timing-based sandbox detection check is also employed as a virtual machine (VM) detection mechanism, silently exiting without performing any collection if detected.

C2 communication. ChocoShell communicates with its C2 server using HTTPS with URI paths designed to blend in with legitimate web traffic. Beacons use /t/pixel.gif?m=<status>, mimicking an image tracking pixel. Additional tooling is fetched from /cdn/chunks/polyfill-7e2b.min.js, disguised as a JavaScript polyfill file. This downloaded module is Base64-decoded and executed in memory via [ScriptBlock]::Create(), providing browser encryption key extraction capabilities, SYSTEM token impersonation, and Defender signature locking. Exfiltrated data is sent by POST to /t/event as GZip-compressed, Base64-wrapped JSON.

Privilege escalation. ChocoShell requires administrative privileges for its most impactful capabilities: SYSTEM token impersonation for Chrome ABE decryption, Volume Shadow Copy Service (VSS) shadow copy creation, Defender signature locking. It implements three silent UAC bypass techniques with ordered fallback:

  1. SilentCleanup task hijack: Writes a malicious command to HKCU\Environment\windir, then triggers the built-in SilentCleanup scheduled task, which resolves %windir% from the user’s environment, executing the threat actor’s command at elevated privilege. The registry value is cleaned up after two seconds to avoid cloud detection.
  2. wsreset.exe COM hijack: Creates a COM handler key in HKCU\Software\Classes and launches the auto-elevating Windows Store reset tool.
  3. sdclt.exe folder hijack: Hijacks HKCU\Software\Classes\Folder\shell\open\command and launches the Windows Backup utility with the /KickOffElev flag.

If none of the silent bypasses succeed (for example, the user is not a local administrator), ChocoShell falls back to a visible UAC prompt via Start-Process -Verb RunAs. Notably, the script also contains a variant designed to execute within the WinGet Desired State Configuration (DSC) host process (ConfigurationRemotingServer), suggesting an attack vector through malicious WinGet DSC configuration used in Windows machine provisioning.

Credential and session theft. Once running with elevated permissions, ChocoShell locks Defender signature updates and systematically harvests data from multiple sources. For Chromium-based browsers (Chrome, Edge, Brave, Opera, Opera GX, Vivaldi), it extracts the master encryption key from the browser’s Local State file, handling both the modern ABE scheme (Chrome v127+) and the legacy data protection API (DPAPI)-only scheme. ABE decryption requires SYSTEM-level DPAPI access, which the malware obtains by impersonating a SYSTEM process token borrowed from winlogon.exe, wininit.exe, or services.exe. Locked browser SQLite databases are accessed through three strategies: shared file access, Volume Shadow Service snapshots, and direct copy as a fallback.

As a parallel collection path, ChocoShell launches Chrome, Edge, and Brave with the –remote-debugging-port flag and issues Network.getAllCookies through the Chrome DevTools Protocol (CDP). This completely bypasses ABE, enabling the browser to perform its own internal decryption and returns plaintext cookie values. To handle privilege issues (SYSTEM-launched browsers inherit the wrong token), the malware creates transient scheduled tasks with TASK_LOGON_INTERACTIVE_TOKEN to launch the browser under the signed-in user’s session. After extraction, the browser is stopped and relaunched with –restore-last-session to avoid alerting the user.

For Firefox family browsers (Firefox, Waterfox, LibreWolf, Floorp, Zen), the malware copies unencrypted cookies.sqlite databases from each profile. Additionally, ChocoShell collects Microsoft 365 and Azure Active Directory (AD) access tokens, refresh tokens, and Web Account Manager (WAM) tokens from .tbres files in the Token Broker cache. Collection of these tokens represents a significant threat to enterprise environments, as threat actors could replay SSO sessions without browser cookies. Additionally, Wi-Fi credentials are harvested via netsh wlan show profile with key=clear.

Exfiltration and cleanup. All collected data is aggregated into a JSON structure, GZip-compressed, Base64-encoded, and sent by POST to the C2’s /t/event endpoint. After exfiltration, all collected data variables are nulled, garbage collection is forced, VSS shadow copies are deleted via Windows Management Instrumentation (WMI), temporary elevation scripts are removed, and all UAC bypass registry keys (already cleaned during escalation) are verified removed.

FruitStone: Operator C2 panel

FruitStone is the web-based C2 panel that Storm-2945 operators use to manage the entire CaptiveCrunch campaign infrastructure. Implemented as a single-page application (HTML and JavaScript) serving as the front-end of the C2 server with all functionality exposed without authentication, FruitStone provides a centralized dashboard for managing compromised endpoints, building and deploying new campaign payloads, and reviewing all collected data (such as screenshots, keystrokes, browser credentials).

Operational cover. The panel is branded as “CloudSync Console” with a footer reading “Acuity Systems, Inc. — Cloud Infrastructure Portal v3.2.1,” designed to appear as legitimate enterprise cloud management software if the panel URL is discovered by defenders or hosting providers. This masquerading extends to the CornFlake agent’s service name (Cloud Sync Service) and description (“Synchronizes files with the cloud storage provider”), creating a consistent cover story across the toolchain.

The CloudSync Console masquerading as Acuity Systems, Inc. sign-in panel.
Figure 5. CloudSync Console panel masquerade

Session management and multi-operator support. FruitStone uses JSON Web Token (JWT)-based authentication, session revocation, and rate limiting with IP blocking to prevent brute force attacks against the panel sign in. Multiple operators could be provisioned with individual accounts, and all active sessions are visible with IP address, user-agent, and creation time to enable operational security awareness across the operators.

Agent management. The panel displays all registered CornFlake agents in a dashboard with real-time status updates via Server-Sent Events (SSE). Each agent card shows comprehensive system information including hostname, username, OS version, CPU, RAM, disk usage, screen resolution, timezone, domain membership, and camera/microphone presence, all collected during the CornFlake posture sweep. Agents are grouped by country and subnet, with geographic distribution visualized on a map.

Operators could interact with individual agents through:

  • Remote shell — Interactive cmd.exe or PowerShell command execution with command history
  • File system browser — Live directory traversal and arbitrary file download from compromised hosts
  • Collection tasking — On-demand screenshot, process list, keylog buffer flush, clipboard dump, security posture survey, ChromeKatz cookie/password extraction, camera capture, and audio recording
  • Configuration push — Live runtime reconfiguration of C2 servers, watch paths, and C2 beacon timing
  • Agent update — In-place implant update by pushing a new CornFlake build to a running agent
  • Agent kill — Remote termination of the CornFlake implant

Campaign builder. A step-by-step wizard enables operators to configure and build new CornFlake payloads directly from the panel:

  1. Identity — Campaign ID, C2 host and port, HTTP base URL, executable file name (svchost32.exe by default), and dropper type (C dropper at ~19 KB, Go stub at ~8 MB, or standalone self-installer)
Figure 6. Identity tab
  1. Capabilities — Toggle individual collection modules: screenshots, process enumeration, keylogging, clipboard monitoring, posture survey, file exfiltration, and ChromeKatz browser credential theft
Figure 7. Capabilities tab
  1. File Paths — Configure targeted directories and file extensions by category (documents, archives, images, code, data, emails, encryption keys)
Figure 8. File paths tab
  1. Evasion — Enable garble symbol randomization (for GoLang payloads), XOR string encoding, GZip upload compression, and debug mode
Figure 9. Evasion tab

Infrastructure management. FruitStone provides management interfaces for three layers of supporting infrastructure:

  • Proxy relays — Multi-proxy C2 relay architecture with TLS certificate tracking (fingerprint, expiry), health checks, connection counts, bytes forwarded, and rotation capabilities that push updated server lists to all online agents
  • Beacon profiles — Configurable timing profiles controlling agent sleep intervals, reconnection delays, TLS Server Name Indication (SNI) spoofing (like teams.microsoft.com), and DNS fallback domains
  • Staging servers — External payload hosting infrastructure with push-to-deploy, file listing, and health monitoring
Figure 10. View of the CloudSync staging servers interface

Device code abuse for cloud access

Since July 16, Microsoft has observed a portion of CaptiveCrunch landing pages redirecting users to device code authentication flow experiences. In these cases, users served these landings might be instructed to enter a device code into a legitimate Microsoft sign-in page, a technique commonly referred to as device code phishing.

Device code authentication is a legitimate OAuth workflow designed for devices that cannot support a traditional sign-in experience. However, threat actors could abuse this flow by initiating an authentication request on behalf of a user then convincing the user to enter an actor-controlled device code into a legitimate Microsoft authentication page. When successful, the victim authenticates the threat actor’s session rather than their own.

This activity is consistent with previously reported device code phishing operations conducted by Midnight Blizzard since August 2024. The observed technique does not appear fundamentally novel; however, integrating device code phishing into captive portal and traffic manipulation operations might increase the likelihood that users perceive the authentication request as legitimate. For additional details on Midnight Blizzard-related device code phishing techniques, see: Storm-2372 conducts device code phishing campaign. To understand other threat actors’ use of device code phishing and associated mitigations, see Inside an AI‑enabled device code phishing campaign.

How to protect against CaptiveCrunch activity

Minimize trust in hospitality and guest networks

When traveling, users should treat hotel, conference, airport, and other guest wireless networks as untrustworthy.

  • Prefer private connectivity (including mobile hotspots, satellite, and eSIM-based cellular data connections) over public Wi‑Fi whenever practical.
  • Consider using enterprise-managed travel routers or hotspot devices that establish encrypted tunnels back to trusted corporate infrastructure before accessing sensitive resources.
  • Avoid downloading software updates, certificates, browser updates, network troubleshooting tools, or security utilities presented through captive portals or other unexpected web prompts.
  • Verify update requests through trusted operating system mechanisms rather than pop-up messages or website prompts.

Strengthen identity and access controls

Organizations should assume that public and hospitality network infrastructure might not be trustworthy and should adopt controls that limit exposure to traffic manipulation, credential theft, and device code phishing.

  • Educate users to recognize ClickFix-style prompts, fake verification checks, and paste-and-run instructions as malicious, especially when they invoke command interpreters or script hosts such as cmd.exe, PowerShell, rundll32.exe, or mshta.exe.
  • Use passwordless solutions like passkeys and implement multifactor authentication (MFA).
  • Only allow device code flow where necessary. Microsoft recommends blocking device code flow wherever possible. Where necessary, configure Microsoft Entra ID’s device code flow in your Conditional Access policies.
  • Implement a sign-in risk policy to automate response to risky sign-ins. A sign-in risk represents the probability that a given authentication request is not authorized by the identity owner. A sign-in risk-based policy can be implemented by adding a sign-in risk condition to Conditional Access policies that evaluates the risk level of a specific user or group. Based on the risk level (high/medium/low), a policy can be configured to block access or force MFA.
    • When a user is a high risk and Conditional access evaluation is enabled, the user’s access is revoked, and they are forced to re-authenticate.
    • For regular activity monitoring, use Risky sign-in reports, which surface attempted and successful user access activities where the legitimate owner might not have performed the sign-in. 
  • Use a Security Service Edge (SSE) solution like Global Secure Access to secure access to any app or resource using network, identity, and endpoint access controls.

Reduce exposure during captive portal registration

Organizations should review what information employees provide to hospitality providers when connecting to guest networks.

  • Do not reuse corporate credentials on hotel, conference, or guest-network registration pages.
  • Where possible, organizations should evaluate whether venue-provided wireless is required for corporate events and conferences.
  • Organizations should minimize unnecessary disclosure of employee identities, organizational affiliations, and travel details when booking accommodations or registering for guest network access, consistent with corporate policy and applicable local requirements.

Microsoft Defender detections and hunting guidance

Microsoft Defender customers can refer to the list of applicable detections below. Microsoft Defender coordinates detection, prevention, investigation, and response across endpoints, identities, email, apps to provide integrated protection against attacks like the threat discussed in this blog.

Microsoft Defender for Endpoint detects Storm-2945 activity under the detection Suspicious activity linked to a Russian state-sponsored threat actor has been detected. However, these alerts might be triggered by unrelated threat actor activity. The following chart lists Microsoft Defender detections specific to the TTPs utilized by Storm-2945 in this attack.

Tactic Observed activity Microsoft Defender coverage 
Initial accessFile download via captive portal redirection Microsoft Defender for Endpoint – Suspicious downloaded file
Initial accessClickFix technique, fake browser or OS update, initial file downloadMicrosoft Defender for Endpoint
– Possible initial access from an emerging threat
– Possible ClickFix activity
PersistenceCornFlake registers a Windows service, a Registry Run key, a scheduled taskMicrosoft Defender for Endpoint
– Suspicious Scheduled Task Process Launched  
– Suspicious scheduled task
– Suspicious file added to run key
– Suspicious service registration

Microsoft Entra ID Protection
– Microsoft Entra threat intelligence
– Verified threat actor IP
Stealth/Defense evasionChocoShell disables AMSIMicrosoft Defender for Endpoint
– Possible Antimalware Scan Interface (AMSI) tampering
Credential accessChocoShell’s theft of browser session cookies, saved passwords, Microsoft 365 SSO tokens, and Wi-Fi credentials.   Device code abuse.Microsoft Defender for Endpoint
– Possible theft of passwords and other sensitive web browser information
– Suspicious DPAPI activity

Microsoft Defender For Identity
– Anomalous OAuth device code authentication activity

Microsoft Defender XDR
– User account compromise via OAuth device code phishing
– Malicious sign in from an IP address associated with recognized attacker infrastructure
– Suspicious Azure authentication through possible device code phishing
CollectionCornFlake monitoring and loggingMicrosoft Defender for Endpoint
– Activity that might lead to information stealer
Privilege escalationChocoShell UAC bypass techniquesMicrosoft Defender for Endpoint
– UAC bypass was detected
– Possible Component Object Model (COM) hijacking

Microsoft Security Copilot

Microsoft Security Copilot is embedded in Microsoft Defender and provides security teams with AI-powered capabilities to summarize incidents, analyze files and scripts, summarize identities, use guided responses, and generate device summaries, hunting queries, and incident reports.

Customers can also deploy AI agents, including the following Microsoft Security Copilot agents, to perform security tasks efficiently:

Security Copilot is also available as a standalone experience where customers can perform specific security-related tasks, such as incident investigation, user analysis, and vulnerability impact assessment. In addition, Security Copilot offers developer scenarios that allow customers to build, test, publish, and integrate AI agents and plugins to meet unique security needs.

Threat intelligence reports

Microsoft Defender XDR customers can use the following threat analytics reports in the Defender portal (requires license for at least one Defender XDR product) to get the most up-to-date information about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide the intelligence, protection information, and recommended actions to prevent, mitigate, or respond to associated threats found in customer environments.

Microsoft Security Copilot customers can also use the Microsoft Security Copilot integration in Microsoft Defender Threat Intelligence, either in the Security Copilot standalone portal or in the embedded experience in the Microsoft Defender portal to get more information about this threat actor.

Hunting queries

Microsoft Defender XDR

Microsoft Defender XDR customers can run the following advanced hunting queries to find related activity in their networks:

Detect file creation after Wi-Fi connectivity test on devices

The following query checks for a file creation on a device within two minutes of the device performing built‑in Network Connectivity Status Indicator (NCSI) test, which occurs when network connectivity is established to a Wi-Fi network with a captive portal. This activity might indicate an attacker’s initial access file presence on a device.

Please note that not all files discovered through this query might be malicious or related to this threat activity.

let ncsi_endpoints = dynamic(["msftconnecttest.com","edge-http.microsoft.com","msftncsi.com","captive.apple.com","clients1.google.com",
    "clients3.google.com","clients4.google.com","clients6.google.com","connectivitycheck.gstatic.com","connectivitycheck.android.com",
    "android.clients.google.com","www.gstatic.com","detectportal.firefox.com","detectportal.brave-http-only.com","cloudflareportal.com",
    "cloudflarecp.com","cloudflareok.com","connectivity-check.warp-svc","connectivity.cloudflareclient.com","spectrum.s3.amazonaws.com",
    "nmcheck.gnome.org"]);
let NCSIEvents = DeviceNetworkEvents
    | where Timestamp > ago(7d)
    | where RemoteUrl has_any (ncsi_endpoints)
    | project NCSI_Timestamp = Timestamp, DeviceId, DeviceName, RemoteUrl, NCSI_ReportId = ReportId, NCSI_InitiatingProcessFileName = InitiatingProcessFileName, NCSI_InitiatingProcessCommandLine = InitiatingProcessCommandLine, NCSI_AccountName = InitiatingProcessAccountName;
let FileDownloadEvents = DeviceFileEvents
    | where Timestamp > ago(7d)
    | where ActionType == "FileCreated"
    | where FileName has_any (".exe",".msi",".zip",".rar",".7z")
    | project Download_Timestamp = Timestamp, DeviceId, FileName, FolderPath, Download_ReportId = ReportId, Download_InitiatingProcessFileName = InitiatingProcessFileName, Download_InitiatingProcessCommandLine = InitiatingProcessCommandLine, Download_AccountName = InitiatingProcessAccountName;
NCSIEvents
| join kind=inner (
    FileDownloadEvents
) on DeviceId
| where Download_Timestamp >= NCSI_Timestamp and Download_Timestamp 

Detect connectivity to Storm-2945 infrastructure

The following query checks for connectivity to Storm-2945 infrastructure observed in this attack activity.

let target_domains = dynamic(["ms365-device.com", "ms365-live.com", "m365-owa.com", "owa-ms365.com"]);
let target_ips = dynamic(["31.57.243.154", "38.146.28.75", "38.146.28.132", "104.194.159.150", "107.189.26.194", "213.145.86.112"]);
DeviceNetworkEvents
| where RemoteUrl has_any(target_domains) or RemoteIP in (target_ips)
| project
    Timestamp,
    DeviceName,
    DeviceId,
    RemoteUrl,
    RemoteIP,
    LocalIP,
    InitiatingProcessFileName,
    InitiatingProcessCommandLine,
    AccountName = InitiatingProcessAccountName,
    ReportId

Detect CornFlake RAT presence on affected systems

The following query checks for the presence of the CornFlake RAT binary.

DeviceProcessEvents
| where FolderPath == "%APPDATA%\\svchost32\\svchost32.exe"
   or FolderPath endswith @"\svchost32\svchost32.exe"
| project Timestamp, DeviceName, DeviceId, FileName, FolderPath, InitiatingProcessFileName, InitiatingProcessCommandLine, AccountName, ReportId

Detect CornFlake RAT Windows service registration

The following query checks for the CornFlake RAT Windows service registration.

DeviceRegistryEvents
| where RegistryKey has @"\SYSTEM\CurrentControlSet\Services\svchost32"
| where ActionType == "RegistryValueSet"
| where (RegistryValueName == "DisplayName" and RegistryValueData == "Cloud Sync Service")
    or (RegistryValueName == "Description" and RegistryValueData == "Synchronizes files with the cloud storage provider")
| project
    Timestamp,
    DeviceName,
    DeviceId,
    RegistryKey,
    RegistryValueName,
    RegistryValueData,
    ActionType,
    InitiatingProcessFileName,
    InitiatingProcessCommandLine,
    InitiatingProcessAccountName,
    ReportId

Microsoft Sentinel

Microsoft Sentinel customers can use the TI Mapping analytics (a series of analytics all prefixed with ‘TI map’) to automatically match the malicious domain indicators mentioned in this blog post with data in their workspace. If the TI Map analytics are not currently deployed, customers can install the Threat Intelligence solution from the Microsoft Sentinel Content Hub to have the analytics rule deployed in their Sentinel workspace.

Detect network IP and domain indicators of compromise using ASIM

The following query checks IP addresses and domain IOCs across data sources supported by ASIM network session parser:

//IP list and domain list- _Im_NetworkSession
let lookback = 30d;
let ioc_ip_addr = dynamic(["213.145.86.112"]);
let ioc_domains = dynamic(["213.145.86.112/t/pixel.gif", "213.145.86.112/cdn/chunks/polyfill-7e2b.min.js", "213.145.86.112/t/event"]);
_Im_NetworkSession(starttime=todatetime(ago(lookback)), endtime=now())
| where DstIpAddr in (ioc_ip_addr) or DstDomain has_any (ioc_domains)
| summarize imNWS_mintime=min(TimeGenerated), imNWS_maxtime=max(TimeGenerated),
  EventCount=count() by SrcIpAddr, DstIpAddr, DstDomain, Dvc, EventProduct, EventVendor

Detect web sessions IP and file hash indicators of compromise using ASIM

The following query checks IP addresses, domains, and file hash IOCs across data sources supported by ASIM web session parser:

//IP list - _Im_WebSession
let lookback = 30d;
let ioc_ip_addr = dynamic(["213.145.86.112"]);
let ioc_sha_hashes =dynamic([“918fa52ae45ed60ba7cc8bdc99c3cbe9ab92e0375ec31fc05d0d4513be11c593”, “be99857449d2856dd5a84e21c8a3d5e0e01456adb44062ddec5a6b4970d8d42c”]);
_Im_WebSession(starttime=todatetime(ago(lookback)), endtime=now())
| where DstIpAddr in (ioc_ip_addr) or FileSHA256 in (ioc_sha_hashes)
| summarize imWS_mintime=min(TimeGenerated), imWS_maxtime=max(TimeGenerated),
  EventCount=count() by SrcIpAddr, DstIpAddr, Url, Dvc, EventProduct, EventVendor

Detect domain and URL indicators of compromise using ASIM

The following query checks domain and URL IOCs across data sources supported by ASIM web session parser:

// file hash list - imFileEvent
// Domain list - _Im_WebSession
let ioc_domains = dynamic(["https://213.145.86.112/t/pixel.gif", "https://213.145.86.112/cdn/chunks/polyfill-7e2b.min.js", "https://213.145.86.112/t/event"]);
_Im_WebSession (url_has_any = ioc_domains)

ChocoShell C2 communications

The following query detects ChocoShell communications with its C2 server using HTTPS with URI paths designed to blend in with legitimate web traffic. Beacons use /t/pixel.gif?m=<status>, mimicking an image tracking pixel.

let lookback = 30d;
let ioc_url_artifacts = dynamic(["/t/pixel.gif?m="]);
_Im_WebSession(starttime=todatetime(ago(lookback)), endtime=now())
| where DstDomain  in (ioc_url_artifacts)
| summarize imWS_mintime=min(TimeGenerated), imWS_maxtime=max(TimeGenerated),
  EventCount=count() by SrcIpAddr, DstIpAddr, Url, Dvc, EventProduct, EventVendor

Indicators of compromise

IndicatorTypeDescriptionFirst seen
ms365-device[.]comDomainCaptiveCrunch DCF redirect2026-07-23
ms365-live[.]comDomainCaptiveCrunch DCF redirect2026-05-14
m365-owa[.]comDomainCaptiveCrunch AitM infrastructure2026-07-20
owa-ms365[.]comDomainCaptiveCrunch AitM infrastructure2026-07-16
31.57.243[.]154  IP addressCaptiveCrunch AitM infrastructure2026-07-16
38.146.28[.]75  IP addressCaptiveCrunch AitM infrastructure2026-07-01
38.146.28[.]132IP addressCaptiveCrunch DNS Resolver2026-07-15
104.194.159[.]150  IP addressCaptiveCrunch AitM infrastructure2026-04-28
107.189.26[.]194IP addressChocoShell C2 / CaptiveCrunch DNS Resolver2026-02-27
213.145.86[.]112  IP addressChocoShell C22026-07-01
918fa52ae45ed60ba7cc8bdc99c3cbe9ab92e0375ec31fc05d0d4513be11c593  File hashCornFlake2026-07-03
be99857449d2856dd5a84e21c8a3d5e0e01456adb44062ddec5a6b4970d8d42cFile hashChocoShell2026-07-10

References

Learn more

For the latest security research from the Microsoft Threat Intelligence community, check out the Microsoft Threat Intelligence Blog.

To get notified about new publications and to join discussions on social media, follow us on LinkedIn, X (formerly Twitter), and Bluesky.

To hear stories and insights from the Microsoft Threat Intelligence community about the ever-evolving threat landscape, listen to the Microsoft Threat Intelligence podcast.

The post CaptiveCrunch: Midnight Blizzard targets travelers worldwide for malware delivery and credential theft appeared first on Microsoft Security Blog.

Why do people (and robots) call but stay silent? | Kaspersky official blog

30 July 2026 at 13:02

Your phone rings, you pick up and say hello. On the other end: total silence. No one answers, and the call abruptly disconnects. If you don’t already use spam call blockers, you’ve almost certainly run into this situation before.

In most cases, these are scam calls. Today, we explain why these calls happen, what the callers want from you, and how to protect yourself. Most importantly, we’ll look at whether you even need to bother protecting yourself against them in the first place.

Who’s calling?

It’s not just scammers on the line — robots, legitimate call center operators, and ordinary folks make these calls too. Let’s break down each type of caller — ordered from best-case to worst-case scenario for your security.

Actual person

The most harmless scenario is that an actual person called you, but their microphone is acting up. Maybe they accidentally muted themselves with their ear, or their smartphone connected to a Bluetooth headset, speaker, or car system that isn’t capturing their voice. Carrier glitches can also mute one side of a call. The caller might have no idea there’s a problem — as far as they know, they are speaking, but no one can hear them. In cases like this, you usually recognize the incoming phone number.

If the call comes from an unknown number, there’s still no need to panic — though the list of those who might be calling gets much longer.

One legitimate possibility is a call center agent who simply didn’t pick up or connect their headset in time. Call center systems are designed to dial numbers faster than agents can wrap up their calls. The system tried to route the call to a human, but no reps were available. That’s why you sometimes have to wait a few seconds before hearing a single word, or why you might hear ringing tones as if you were the one making the call.

Robot or AI

Silence on the line is a common sign of robocalls. Robots test whether a phone number is active and, if it is, pass it along to a human — meaning a real sales rep (or scammer) will call you back in the next few days. It’s worth noting that scammers aren’t the only ones making these pinging calls. Legitimate call centers use the exact same tools to reduce the workload on their live agents.

An AI agent could also be behind the silent call. To the person answering, there’s no practical difference: the call looks identical to one made by a standard bot. However, AI can do more than just auto-dial numbers — it can analyze your response and use that data to decide whether your number is active and ready to be handed off to a live person for follow-up.

Unwanted caller

Now we get to the real threat. Perhaps one of the most dangerous and unpleasant sources of silent phone calls is a scammer. A quick, silent call like this can actually be the groundwork for a long, elaborate attack with cover stories about loans, government agencies, other fraudsters, even law enforcement.

Debt collectors might also be calling and staying quiet. Your number could end up on their radar if you, your family, or close contacts have outstanding debts. In these cases, a silent call is often used as a tactic for psychological pressure.

A similar technique is used in stalking. While silent calls cause no direct harm on their own, they can be leveraged to induce anxiety, create a feeling of being constantly watched, and cause ongoing emotional distress.

Why do they call and stay silent?

When you pick up, you likely respond out of habit with a quick “Hello?” or “Hi there.” That’s all it takes for the other party to gather a wealth of data. While this information used to be difficult to process, the rise of artificial intelligence has made the task significantly easier. Let’s look at what someone can learn about you from just one spoken word:

  • Region, accent, and location. Scammers are sophisticated and cunning. Their tactics are often tailored by region — targeting residents of specific countries or even regions within them. This is especially relevant in places like India or South Africa, which have 22 and 11 official languages, respectively.
  • Approximate age and gender. While a human listener might easily confuse a teenager’s voice with a young woman’s or misjudge someone’s age entirely, AI is far better at picking up on subtle vocal nuances. Knowing your age and gender helps scammers refine their playbook for future social engineering attacks.
  • Times you’re available. If you answer the phone in the morning, afternoon, or late at night, attackers can schedule their follow-up call during the exact time window when you’re most likely to pick up.
  • Likelihood of a successful attack. AI can automatically assess the potential value of a target. For instance, if someone answers quickly, speaks calmly, and doesn’t immediately hang up on unknown numbers, they’ll likely be assigned a higher priority for follow-up calls by live scam operators.

Back to the “why do they call and stay silent”, the main reason is to harvest biometric data. Just a few seconds of recorded audio can help cybercriminals create a voice deepfake. While one or two words might not yield a convincing clone on their own, attackers can stitch together recordings from multiple silent calls to build a believable replica.

This technology is already being used in real-world scams. Impersonating a relative, colleague, or boss, fraudsters can urgently ask you to send them money, to share a two-factor authentication code for government services, or to complete some other seemingly innocuous request. The more realistic the deepfake sounds, the harder it is to spot the scam — especially when backed by a convincing backstory.

What to do if you get a silent call?

If you answer a call, say a few words, and hang up, there’s no need to panic. However, that brief interaction can confirm to attackers that your number is active and that you’ll answer calls from unknown numbers. As a result, your phone number could end up on target lists for future spam or scam campaigns. That said, it’s important to remember that a single silent call poses no immediate security threat.

Here are a few tips to help you stay calm and avoid falling for scam tactics if those silent calls are becoming a problem:

  • Don’t answer calls from unknown or hidden numbers. Here’s a helpful tip: if someone genuinely needs to reach you, they’ll find another way to do so, or keep calling from the exact same number at various times. Scammers almost always dial from different numbers, while automated bots operate on a rigid schedule — like calling every day at precisely 8:05 AM.
  • Don’t rush to call back. Scammers often count on proactive victims who are curious enough to return calls from unfamiliar numbers. On top of that, calling back could end up costing you money if it’s a premium-rate number.
  • Don’t speak first. Wait for the caller to greet you before starting a conversation. If you hear muffled noise or complete silence on the line, hang up and save yourself the hassle — it’s likely a scam.
  • Block unknown numbers — even after the call. If you picked up and realized the call could be risky, it’s best to block the number right away. You can use the built-in features on most modern smartphones to do this.
  • Don’t share your number everywhere. Phishing sites, fly-by-night web pages, and sketchy giveaways often exist solely to collect your personal data. When filling out forms online, it doesn’t hurt to use a burner or secondary number.
  • Get a second phone number. Separate your daily life between two numbers. Use your main line strictly for family, friends, and work contacts, and reserve the secondary line for deliveries, online marketplaces, and general web sign-ups.

Further reading on scammers and deepfakes:

ClickFix on macOS: how the Terminal-based attack works, and how to protect yourself | Kaspersky official blog

AI is getting better and better at solving CAPTCHAs. This makes website creators — who still need to verify that they’re dealing with humans rather than bots — come up with increasingly sophisticated proof-of-humanity checks. It seems an average user would no longer be surprised if asked to recite a poem — or, say, dance Gangnam Style — just to access certain websites. The latter could double as an age check, but I digress.

Attackers have learned to exploit this variety of sometimes bizarre checks to their advantage. In our blog, we’ve talked more than once about the ClickFix attack technique, which is all about slipping a malicious instruction to the victim under the guise of yet another CAPTCHA. Historically, this technique has been used to attack users of Windows-powered devices. However, researchers recently discovered a campaign that targets macOS users. In this post, we talk in more detail about the ClickFix attack technique, the new campaign aimed at Mac users, and the criminals’ goals.

What is the ClickFix attack technique?

Many common attacks and scams rely on social engineering, or more simply put — manipulation. Instead of looking for software vulnerabilities, attackers try to trick the user into doing the dirty work themselves: opening a malicious file, clicking a link to a fake website, sharing sensitive data, or running a harmful command.

The simplest example of social engineering is scam calls, where criminals pose as a boss, neighbor, bank security specialist, police officer… the list goes on almost indefinitely. And if you think that only, let’s say, not-so-smart users fall for these tricks, you’re wrong: social engineering has been used to hack the CIA chief’s email, hijack the X (Twitter) accounts of Elon Musk and Joe Biden, and steal half a billion dollars. In our post, They’re reading you like a book: scammers’ favorite tricks, we take a close look at their favorite techniques — give it a read so you don’t end up sharing company with those famous victims.

The ClickFix attack also relies on social engineering, except the scammers aren’t betting on the victim’s fear of an authority figure, but rather on their trust in technology and their habit of following instructions — even when they don’t quite make sense.

In a classic ClickFix scenario, a user visits a compromised or fake website and, instead of the expected page, sees a notification that there’s an issue. The site might claim that to continue, you need to complete an extra verification check, update your browser, or fix an error.

A typical ClickFix attack scenario

ClickFix: how to infect your own computer with malware in three easy steps. One of the classic variations of the attack targeting Windows users Source

Next, the victim is prompted to follow a few simple steps that look harmless enough at first glance. Usually, this involves copying some text from the attackers’ website, opening the Run window, pasting the text there, and hitting Enter.

In reality, the text is a malicious command that downloads and runs malware on the device. Since the user carries out all the steps themselves, the operating system’s security mechanisms and built-in warnings are often dismissed as just another part of the instructions. In our blog, we’ve covered the typical pretexts used to trick victims into taking dangerous actions; you can read more about them here.

The ClickFix attack scheme quickly began spawning various spin-offs, such as FileFix and ConsentFix. Until recently, the victims of ClickFix and its variants were mostly Windows users, while Mac fans encountered it much more rarely. But lately, the number of ClickFix attacks targeting Apple device owners has been on the rise.

How does the ClickFix attack on macOS work?

The ClickFix attack on Macs, as documented by cybersecurity researchers, begins with the classic fake CAPTCHA scenario. To pass the proof-of-humanity check, attackers prompt the user to copy a command, open Terminal, and paste the text into it.

Malicious ClickFix command for macOS

The contents of the command that the user is prompted to run via Terminal. Source

The more interesting part is what happens after the malicious command is run. First, it downloads a malicious DMG — the standard format for disk images containing installation files in macOS — from a remote server, and saves it to the /tmp temporary folder under a random name. Then the script mounts the disk image without showing it in Finder or creating a desktop icon — keeping it hidden from the user. After that, the script searches the disk image for an app or installation package, and automatically launches it once found.

One case documented in the researchers’ findings involved the widespread AMOS (Atomic macOS Stealer) infostealer being distributed this way. To gain extra privileges on the system, the stealer Trojan displays a fake macOS system authentication window tricking the user into willingly typing in their password.

What are the attackers’ goals?

After the malware is installed, the attackers steal literally everything they can get their hands on from the victim’s device. Atomic macOS Stealer extracts sensitive information stored in Chromium-based browsers (Google Chrome, Microsoft Edge, Brave, Opera, Arc, Vivaldi, CocCoc, and Yandex), as well as Firefox-based ones (LibreWolf, SeaMonkey, Tor Browser, Waterfox, and Zen Browser), such as the following:

  • Cookies
  • Saved logins and passwords
  • Auto-fill data
  • Saved credit and debit cards
  • Browser profile data

On top of all that, the attackers also steal PDF, TXT, and RTF files from the victim’s device. The criminals are especially interested in crypto apps; specifically: desktop crypto wallets like Exodus, Electrum, Atomic Wallet, Wasabi Wallet, Bitcoin Core, Litecoin Core, DashCore, Guarda, Binance Wallet, Dogecoin Wallet, and Tonkeeper. The malware also gathers data from more than 200 cryptocurrency-related browser extensions.

But that’s still not everything…

It also targets the Telegram and Discord desktop apps. The malware doesn’t spare Apple’s ecosystem either — stealing Safari cookies, notes from Apple Notes, and passwords stored in the built-in Apple Keychain.

What Atomic macOS Stealer does after infection

Once a device is infected, Atomic macOS Stealer whisks away everything valuable. Source

All of the collected information is added to a ZIP archive and uploaded to the attackers’ server. In addition, the malware replaces legitimate versions of hardware crypto wallet apps — specifically Ledger Wallet and Trezor Suite — with malicious fakes.

Together, this trove of data gives attackers broad opportunities to further compromise accounts, steal digital assets, and launch new attacks on behalf of the victim.

How do I avoid becoming a victim of ClickFix?

As social engineering attacks continue to grow, users need to be more vigilant than ever. That goes for everything from chatting with strangers on the phone or in messaging apps to everyday online activity.

  • Never paste commands into your Terminal just because a website asks you to — whether it’s to pass a verification check, confirm your identity, or view hidden content. No legitimate website will ever ask you to enable its features by manually running commands Terminal.
  • Never enter your macOS administrator password unless you completely understand what app is asking for it.
  • Regularly install macOS security updates, or better yet, set them to install automatically by going to System SettingsGeneralSoftware Update and clicking the i icon next to Automatic Updates. While recent versions of macOS may warn you when you try to paste suspicious or malicious commands into Terminal, this isn’t a reliable feature. For example, the malicious code shown in the screenshot above didn’t trigger any warnings at all on macOS Tahoe 26.5.2.
  • Trust the warnings from your operating system and security software rather than the instructions — or even the demands — of websites and apps.
  • Install a reliable security suite for macOS. It’ll warn you and block malicious activity if you land on a suspicious website.
  • Use secure password manager to keep your login credentials and crypto assets safe from cybercriminals.

Read our posts to learn about other threats facing Apple device owners:

What&#8217;s your data worth on the dark web? (Lock and Code S07E15)

27 July 2026 at 16:35

This week on the Lock and Code podcast…

Twenty years ago, a British mathematician named Clive Humby popularized a phrase that came to describe data’s relationship with the entire global economy: “Data is the new oil.”

Pithy as the phrase sounds, it is undeniably true.

Data steers decisions at businesses of every size. Data created entirely new industries built around its capture. And, for a select number of companies, data has produced billions—if not trillions—of dollars in value.

So how is it that, on the dark web, your stolen identity can be purchased for just 95 cents?

That’s what a Malwarebytes researcher found last month after spending 48 hours inside the dark web to investigate cybercrime. Across a variety of forums and directories, he found subscription plans for malware that steals information once implanted on a device. He found guides for deploying social engineering scams. He found people selling their services to build fake websites that trick people into handing over their usernames and passwords. And he found one of the dark web’s most traded commodities—personal data, packaged together about individual people, to help a cybercriminal commit identity fraud.

These packages are called “fullz.” For victims in the United States, a fullz contains a full name, Social Security Number, date of birth, address, and other personal details. That is enough, on its own, for a cybercriminal to potentially open a bogus line of credit, file a fake tax return, access financial accounts, or obtain medical services under someone else’s name.

As we wrote on Malwarebytes Labs:

“For less than the cost of a cup of coffee, a cybercriminal can buy enough information to devastate someone’s financial life.”

It’s the kind of risk that could scare anyone, especially considering the scale behind it. In just the first six months of 2026, Malwarebytes found more than 7,500 compromised data sets on the dark web containing more than 8.4 billion records.

And yet, even today, cybersecurity professionals still get asked why anyone should bother protecting their data.

The public, understandably, are exhausted. With data breaches happening every week—if not every day—cybersecurity can start to feel pointless. With young people unable to build financial security, they start believing that they have nothing worth stealing. And with Big Tech already collecting our every movement, behavior, click, and concern, people understandably feel powerless to fight any kind of data abuse, be it corporate or criminal.

So today’s episode approaches the question from a different direction. This isn’t about why you should protect yourself—plenty of company websites will tell you that, and most of them rely on fear. This is about why hackers want your data in the first place.

Today, on the Lock and Code podcast, host David Ruiz explains how cybercriminals turn a single repeated password into account takeover, how a screenshot of your house from Google Maps became a tool in extortion emails, and why the most benign information about you—an address, an age, one public photo—is often the most useful data a stranger can buy.

Tune in today to listen to the full episode.

Show notes and credits:

Intro Music: “Spellbound” by Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
http://creativecommons.org/licenses/by/4.0/
Outro Music: “Good God” by Wowa (unminus.com)


Listen up—Malwarebytes doesn’t just talk cybersecurity, we provide it.

Protect yourself from online attacks that threaten your identity, your files, your system, and your financial well-being with our exclusive offer for Malwarebytes Premium for Lock and Code listeners.

What&#8217;s your data worth on the dark web? (Lock and Code S07E15)

27 July 2026 at 16:35

This week on the Lock and Code podcast…

Twenty years ago, a British mathematician named Clive Humby popularized a phrase that came to describe data’s relationship with the entire global economy: “Data is the new oil.”

Pithy as the phrase sounds, it is undeniably true.

Data steers decisions at businesses of every size. Data created entirely new industries built around its capture. And, for a select number of companies, data has produced billions—if not trillions—of dollars in value.

So how is it that, on the dark web, your stolen identity can be purchased for just 95 cents?

That’s what a Malwarebytes researcher found last month after spending 48 hours inside the dark web to investigate cybercrime. Across a variety of forums and directories, he found subscription plans for malware that steals information once implanted on a device. He found guides for deploying social engineering scams. He found people selling their services to build fake websites that trick people into handing over their usernames and passwords. And he found one of the dark web’s most traded commodities—personal data, packaged together about individual people, to help a cybercriminal commit identity fraud.

These packages are called “fullz.” For victims in the United States, a fullz contains a full name, Social Security Number, date of birth, address, and other personal details. That is enough, on its own, for a cybercriminal to potentially open a bogus line of credit, file a fake tax return, access financial accounts, or obtain medical services under someone else’s name.

As we wrote on Malwarebytes Labs:

“For less than the cost of a cup of coffee, a cybercriminal can buy enough information to devastate someone’s financial life.”

It’s the kind of risk that could scare anyone, especially considering the scale behind it. In just the first six months of 2026, Malwarebytes found more than 7,500 compromised data sets on the dark web containing more than 8.4 billion records.

And yet, even today, cybersecurity professionals still get asked why anyone should bother protecting their data.

The public, understandably, are exhausted. With data breaches happening every week—if not every day—cybersecurity can start to feel pointless. With young people unable to build financial security, they start believing that they have nothing worth stealing. And with Big Tech already collecting our every movement, behavior, click, and concern, people understandably feel powerless to fight any kind of data abuse, be it corporate or criminal.

So today’s episode approaches the question from a different direction. This isn’t about why you should protect yourself—plenty of company websites will tell you that, and most of them rely on fear. This is about why hackers want your data in the first place.

Today, on the Lock and Code podcast, host David Ruiz explains how cybercriminals turn a single repeated password into account takeover, how a screenshot of your house from Google Maps became a tool in extortion emails, and why the most benign information about you—an address, an age, one public photo—is often the most useful data a stranger can buy.

Tune in today to listen to the full episode.

Show notes and credits:

Intro Music: “Spellbound” by Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
http://creativecommons.org/licenses/by/4.0/
Outro Music: “Good God” by Wowa (unminus.com)


Listen up—Malwarebytes doesn’t just talk cybersecurity, we provide it.

Protect yourself from online attacks that threaten your identity, your files, your system, and your financial well-being with our exclusive offer for Malwarebytes Premium for Lock and Code listeners.

Email threat landscape: Q2 2026 trends and insights

The second quarter of 2026 (April–June) was largely defined by the continuing downstream effects following Microsoft’s Digital Crimes Unit-led disruption efforts against the Tycoon2FA phishing-as-a-service (PhaaS) platform in March. Phishing volume linked to the platform fell 92% from pre-disruption averages, including QR code phishing and CAPTCHA-gated phishing both declining from their March highs. Despite ongoing efforts to rebuild operations, Tycoon2FA did not recover its previous scale or influence during Q2, and no single service emerged to replace the platform at comparable scale.

These trends reflect both the measurable impact that disruption operations can have on phishing ecosystems and the adaptability of threat actors as they diversify delivery channels. At the same time, Microsoft Threat Intelligence observed continued growth in Teams-based social engineering, particularly voice phishing (vishing), with weekly malicious call attempts reaching nearly ten times the mid-2025 baseline by the end of the quarter. This activity illustrates how threat actors continue to expand beyond email into trusted workplace communication platforms where communications may appear more trustworthy to users.

Microsoft detected approximately 7.6 billion email-based phishing threats throughout the quarter, with monthly volumes declining modestly from 2.7 billion in April to 2.4 billion in June. Credential phishing remained the dominant objective behind malicious payloads, while business email compromise (BEC) activity largely returned to historical norms after a brief, anomalous surge in April. Notable campaigns observed during the quarter also demonstrated how threat actors combine automation, trusted services, and multi-stage delivery chains to scale operations. These campaigns ranged from an automated BEC campaign that reached more than 67,000 users across 42,000 organizations in under three hours, to a multi-stage phishing campaign that used nested EML files, calendar invitations, and a Microsoft authentication redirect to deliver malware.

This blog provides a view of email threat activity across the second quarter of 2026, highlighting key trends in phishing techniques, payload delivery, and threat actor behavior observed by Microsoft Threat Intelligence. We examine shifts in QR code and CAPTCHA-gated phishing activity, malicious payload trends, BEC activity, the growth of Teams-based threats, and notable campaigns observed during the quarter. We also provide recommendations and Microsoft Defender detections to help organizations identify and mitigate evolving threats while prioritizing defensive measures.

Tycoon2FA Q2 disruption impact

The disruption operation that Microsoft’s Digital Crimes Unit launched against Tycoon2FA infrastructure in early March continued to produce measurable results throughout Q2 2026. After falling 15% in March and another 22% in April, Tycoon2FA-linked phishing volume dropped 74% in May to just 1.5 million messages, then fell another 20% in June to 1.2 million, by far the lowest monthly volumes observed in at least a year. For reference, the average monthly volume of phishing messages linked to Tycoon2FA during the second half of 2025 was 15.1 million. By the end of Q2, volumes were running at roughly 8% of that baseline, representing a 92% total decline since the disruption operation began.

The diagram shows a descending line representing the number of phishing emails received each month, starting from 25 million in July and decreasing to nearly 0 by December.
Figure 1. Tycoon2FA monthly malicious messages volume (July 2025–June 2026)

Tycoon2FA’s influence across two primary phishing tactics, QR code lures and CAPTCHA-gated landing pages, also continued to decline throughout the quarter:

  • CAPTCHA-gated phishing: Tycoon2FA’s share of CAPTCHA-gated phishing sites fell from 41% in March to 16% in April and 12% by June, down from a peak of 76% in December 2025.
  • QR code phishing: The share of QR code campaigns redirecting to Tycoon2FA domains decreased from 20% in March to 17% in April and 14% by June, down from a peak of 33% in November 2025.

These declines indicate that the platform’s customer base has not migrated to replacement infrastructure at anything close to the scale they previously operated.

After being forced off Cloudflare, which had provided anti-analysis protection that made Tycoon2FA pages harder to scan and take down, the service continued to rely on infrastructure hosted on the .RU top-level domain (TLD), a shift that began in late March. More than 40% of newly observed Tycoon2FA domains used .RU registrations throughout Q2. While this reflects an ongoing effort to find replacement hosting, Tycoon2FA’s role in the phishing ecosystem has nonetheless been significantly diminished and the pace of recovery has been slow.

QR code phishing attacks

After peaking at 18.7 million attacks in March, the highest monthly volume in at least a year, QR code phishing declined for three consecutive months in Q2. Volume fell 7% in April to 17.4 million, then dropped more sharply in May (-38%) and June (-22%), closing the quarter at 8.3 million attacks. By June, QR code phishing had returned to levels last seen in mid-2025.

The line graph shows a steady increase in phishing emails received, starting from around 1 million on January 1, 2026, peaking around 6 million around April 9, before declining back down towards 1 million by the end of June.
Figure 2. Trend of QR code phishing attacks by weekly volume (January 2026–June 2026)

The delivery methods used in QR code attacks shifted notably during Q2. PDF attachments remained the dominant vehicle throughout, but their dominance weakened after April:

  • PDF attachments peaked at 79% of QR code attacks in April before falling to 59% in May and 58% in June. By raw volume, malicious PDFs containing QR codes dropped more than 60% between April and June.
  • DOC/DOCX attachments moved in the opposite direction, increasing 30% in May to account for 38% of QR code payloads, the highest share since December 2025. By June, DOC/DOCX payloads reached 40% of QR code attacks. This swap between PDF and DOC/DOCX dominance is a pattern that has recurred throughout the past year, as operators appear to rotate between delivery formats.
  • Email-embedded QR codes, which had surged 336% in March and accounted for 5% of QR code attacks, effectively disappeared in Q2. This delivery method dropped to near-zero across all three months, leaving QR code phishing almost entirely an attachment-based tactic.
The graph shows PDF attachments peaking in April at 79% before declining to 58% in June, while DOC attachments rising from around 20% in April up to 40% in June, and other attachments remained under 10% throughout the last 6 months.
Figure 3. QR code phishing delivery method share by month (January-June 2026)

CAPTCHA-gated phishing tactics

After accumulating to nearly 12 million attacks in March, the highest monthly volume observed over the past year, CAPTCHA-gated phishing declined sharply throughout Q2. Volume fell 32% in April to 8.2 million, then dropped another 65% in May and 24% in June, closing the quarter at just 2.2 million attacks. Since the March peak, CAPTCHA-gated phishing has fallen more than 81%, reaching its lowest monthly volume in more than a year.

The graph shows a decline in the number of phishing emails from 12 million in March to 2.2 million by June.
Figure 4. CAPTCHA-gated phishing volume (January 2026–June 2026)

The rapid rotation of delivery methods that characterized Q1 continued into Q2, with no single payload type maintaining the top position for more than one or two months:

  • PDF attachments surged to 63% of CAPTCHA-gated attacks in April, the highest single-payload share observed in the past year, after more than quadrupling in March. This dominance was short-lived, however. PDF volumes dropped 69% in May and another 70% in June, falling to just 22% of attacks by the end of the quarter.
  • HTML attachments, which had been a major delivery vector through January (37% of attacks), declined sharply during Q2. After declining to 8% in April, HTML payloads fell to just 3% in May before recovering slightly to 5% in June, their lowest sustained share in at least a year.
  • SVG files reached their lowest observed volume in April (5% of attacks) before rebounding to 12% in May and 26% in June. While still well below the levels seen when Tycoon2FA actively used SVG files, this gradual recovery bears monitoring.
  • Email-embedded URLs reclaimed the top position in June for the first time since December 2025, accounting for 30% of CAPTCHA-gated attacks. This was more a function of every other delivery method declining in raw volume than a resurgence in URL-based delivery. The actual volume of URL-delivered CAPTCHA-gated phish in June was still far lower than most months over the past year.
  • DOC/DOCX files declined from their March spike, falling steadily from 15% to 10% of attacks over the quarter.
The bar chart displays PDF attachments peaking at over 60% in April before declining to closer to 20% by June, while SVG files and URLs rose from April lows to closer to 30% by June, DOC files hovered around 15% throughout the quarter, and HTML attachments and other payload types landed under 10% by June.
Figure 5. CAPTCHA-gated phishing distribution method share by month (January-June 2026)

Tycoon2FA’s continued decline was a significant factor in the overall volume reduction. The platform’s share of CAPTCHA-gated phishing fell from 41% in March to 16% in April, 18% in May, and 12% by June, down from a peak of 76% in December 2025. No single service has emerged to fill the gap at comparable scale, contributing to the sustained decline in CAPTCHA-gated phishing activity overall.

Malicious payloads

Credential phishing continued to dominate the malicious payload landscape throughout Q2, accounting for 94–96% of all payload-based attacks each month. These credential phishing payloads either linked users to phishing pages or locally loaded spoofed sign-in screens on a user’s device. Traditional malware delivery represented just 4–6% of payloads, consistent with its long-term decline.

HTML and PDF attachments remained the two most common malicious payload types across the quarter, together accounting for roughly 60–70% of all payload-based attacks each month:

  • HTML attachments held the top position across all three months at 35–41% of attacks. After peaking in April, HTML payload volume declined 33% in May and another 17% in June.
  • PDF attachments consistently ranked second at 24–31% of attacks. PDF volume was relatively stable in April before declining 41% in May and 4% in June.
  • SVG files continued the decline that has tracked closely with Tycoon2FA’s diminishing activity. After peaking at 23% of malicious payloads in July 2025, SVG’s share fell to around 7% by Q2, consistent with SVG’s historical role as a preferred Tycoon2FA payload format.
  • DOC/DOCX and ZIP/GZIP files oscillated without a clear directional trend. DOC/DOCX increased 26% in May before falling 17% in June, while ZIP/GZIP attachments declined 48% in April, rebounded 27% in May, then dropped 40% in June.
  • ICS files (calendar invitations), while still a small share of overall payload volume (roughly 4%), nearly quadrupled in June (+277%). These attacks take advantage of the fact that calendar invitations are processed differently than standard email attachments and can inject malicious links into a user’s calendar without requiring an explicit open-and-click interaction.
  • EXE files continued to decline, falling to their lowest monthly volume in June, reflecting the broader shift away from traditional malware delivery via email attachments.
The pie chart displays a breakdown of file types, with HTML (38%), PDF (27%), DOC/DOCX (9%), SVG (8%), ZIP/GZIP (6%), RAR (2%), ICS (2%), and Other (8%).
Figure 6. Malicious payload file type (Q2 2026)

Business email compromise

April 2026 produced the most anomalous BEC data point in more than a year: nearly 9 million attacks, a 121% increase from March and more than double any previous month. The spike was short-lived as volume fell 62% in May to 3.4 million and settled at 3.9 million in June, both figures consistent with the monthly baseline that had held throughout the prior year. The April surge appeared to be driven by a small number of high-volume campaigns rather than a fundamental escalation in BEC activity.

The diagram illustrates the number of BEC attacks peaking in April at over 9 million attacks before sharply declining in May and June down to 3.9 million attacks.
Figure 7. Monthly BEC attack volume (January 2026–June 2026)

The composition of BEC attacks remained consistent throughout Q2. Generic outreach messages (like “Are you at your desk?”) accounted for 87–92% of initial contact emails each month, while explicit requests for specific financial transactions or documents represented just 3–8%. This pattern underscores that BEC operators overwhelmingly favor establishing conversational rapport with targets before making fraudulent requests, rather than leading with direct financial asks.

The pie chart displays a breakdown of BEC outreach lures, with Generic outreach content (90%), Generic task request (4%), Payroll update (2%), gift card request (2%), invoice payment (2%), and other (0%).
Figure 8. Initial BEC email content by type (Q2 2026)

Within the smaller subset of explicit financial requests, the most notable trend was the near-disappearance of fake invoice payment requests:

  • Invoice payment requests fell 67% in May and another 77% in June, reaching their lowest volume in more than a year. By June, invoice-themed BEC accounted for less than 0.4% of all attacks, down from around 3.6% in March.
  • Payroll update requests declined moderately across the quarter, from roughly 4% of attacks in March to 2.3% by June.
  • Gift card requests remained at roughly 1–4% of attacks, with no clear directional trend.

Microsoft Teams threats

While email remains the dominant initial access vector, threat actors increasingly abused Microsoft Teams during Q2 to deliver social engineering, phishing, and malware payloads. Unlike email, Teams traffic typically bypasses secure email gateways and benefits from the perceived legitimacy of a colleague-initiated chat, which can make lures particularly effective in this environment.

Teams-based phishing volume climbed steadily throughout Q2, with the average number of detected attacks rising 19% from March to April, holding roughly flat into May (+1%), then increasing another 10% into June. Financial and executive impersonation has remained largely absent from Teams-based attacks over the past several months.

A line chart depicting an upward trend of Teams call attempts, starting around 2,000 attempts in early January and climbing up closer to 10,000 attempts by June 29.
Figure 9. Weekly observed malicious Microsoft Teams calls (January-June 2026)

The dominant lure theme remained technical support impersonation, with attackers posing as an employee’s information technology (IT) help desk, typically warning of an impending account lockout. However, the way attackers presented themselves continued to evolve:

  • Display names shifted away from IT- or help desk-branded identities. For the second consecutive month, more than half (52%) of Teams-based phishing attacks in June used generic display names rather than obvious IT support impersonation.
  • Attacker email addresses associated with these chats moved away from support-themed domains toward software-as-a-service (SaaS) terminology, scan/update language, and infrastructure keywords. This shift may align with the broader rise of ClickFix-style attacks adopting update-fix and similar themes.
Bar chart showing the types of Teams call impersonation attempts across April, May, and June. General display name attempts took the majority at 42% in April climbing to 52% by June. Help desk impersonations grew from 22% in April up to 31% by June while IT support impersonations declined 32% in April down to 16% in June. Other impersonation attempts made up 4% of attacks in April and declined down to 1% by June.
Figure 10. Malicious Teams call impersonation percentage (Q2 2026)

Vishing through Teams showed the steepest growth of any threat category tracked in this report during Q2. Average weekly malicious call attempts rose 31% from April to May and another 27% into June, with the final two weeks of June recording the two highest weekly volumes on record. Since the beginning of 2026, weekly vishing attempts have increased roughly 80% and now run at nearly ten times the mid-2025 baseline. Attackers time these calls deliberately when targets are most likely to be online and active, with the heaviest activity falling between 14:00 and 20:00 UTC, Monday through Friday, with near-zero weekend activity. Notably, a growing share of these calls go unanswered, end quickly, or are rejected outright, partly reflecting Microsoft’s ongoing efforts to harden the Teams attack surface and improve protections against social engineering abuse.

Notable phishing campaigns

The following campaigns were observed during the quarter and highlight notable credential phishing, BEC, and malware delivery activity. For analysis of a separate code of conduct-themed credential phishing campaign observed in April of Q2, see Breaking the code: Multi-stage ‘code of conduct’ phishing campaign leads to AiTM token compromise.

Automated BEC campaign scales aging report and payroll diversion lures

On June 1, 2026, Microsoft Defender Research observed a high-volume BEC campaign that used automation to operate at scale. Over a send window of under three hours (14:08–16:52 UTC), the actor reached more than 67,000 users across more than 42,000 organizations, almost exclusively in the United States. Targeting spanned a broad range of industries rather than a single vertical, most notably retail and consumer goods (17%), technology and software (15%), and financial services (14%). The campaign ran two lures in succession from shared infrastructure: arequest impersonating sales executives to obtain aging report data and customer contact details, and a payroll diversion pretext impersonating the CEO or President to redirect salary payments to attacker-controlled bank accounts.

A line chart illustrating the number of emails sent in both the aging reports and payroll diversion campaigns over time. The aging reports campaign started around 14:07 UTC, peaked around 14:40 UTC, and then declined at the same time that the payroll diversion campaign started ramping up.
Figure 11. Timeline of campaign messages sent by minute, separated by lure theme

Delivery was fully scripted. The messages were generated programmatically using Python’s email.mime library, identifiable from its default MIME boundary format (===============[integer]==), and dispatched through the Amazon Simple Email Service (SES) API rather than a manual webmail interface, as indicated by the SES Feedback-ID and Message-ID formats. This allowed the actor to iterate through a recipient list and inject per-message variables (like spoofed executive display names, recipient addresses, and unique tracking identifiers) at volume. Messages were sent from a DomainKeys Identified Mail (DKIM)-configured Slovak domain (ecajovna[.]sk) through SES, so they passed Sender Policy Framework (SPF) and achieved DKIM alignment. Neither lure contained a malicious link or attachment; both relied on eliciting a reply to attacker-controlled mailboxes that mimicked legitimate providers (ilyff[.]com, j-gmails[.]com, x2mails[.]com).

Automation also extended to targeting and follow-up. The actor addressed generic role-based mailboxes (like “ar”, “accountsreceivable”, “hr”, “payroll”) rather than named individuals, reducing per-target effort. Each message embedded a 1×1 open-tracking pixel served from an Amazon SES engagement subdomain, with per-message identifiers that let the actor confirm which recipients opened the email and prioritize follow-up against those targets. The combination of scripted message generation, API-based bulk delivery, role-based targeting, and automated engagement tracking allowed a single actor to run a personalized, financially motivated BEC operation at a scale not practical to execute manually.

A user's email requesting a copy of the most recent AR Aging Collection Report, including customer contact details.
Figure 12. Rendered example of aging report email used in this campaign
A supposed user is requesting assistance to update their salary payment details due to a change in their banking information.
Figure 13. Rendered example of payroll diversion email used in this campaign

Staff update campaign with nested EML file and calendar invitation leads to BAT file dropper

Between June 14–15, 2026, Microsoft Defender Research observed a phishing campaign targeting more than 107,000 users across nearly 19,000 organizations, almost exclusively in the United States. The campaign targeted a broad range of industries rather than a single vertical, most notably financial services (17%), technology and software (14%), and retail and consumer goods (14%). Emails impersonated an internal “Internal Affairs – Financials & Staff Updates” function at the recipient’s own organization, with the display name and subject line both opening with the recipient’s organization name and closing with constant trailing text. The messages were sent from a Postfix host on 9i6pokerdepot[.]com routed through Barracuda’s outbound mail service, and DKIM passed cleanly for the sending domain.

An email with a header indicating it is an internal employee briefing and meeting summary, with placeholders for confidential information and a request to download and review an attachment for further details.
Figure 14. Rendered sample of initial campaign email

The visible email body contained minimal content. One line told the reader to download the attached file for the meeting summary, followed by a confidentiality notice. Each message carried two attachments: a nested EML posing as a Teams archive recording, and an ICS calendar invite addressed to placeholder administrative accounts at the recipient’s domain. The nested EML’s file name retained an unfilled template token ( {{DATE2}} ), indicating a per-recipient templating tool.

When opened, the EML displayed a voicemail notification with a single action button. That button pointed to Microsoft’s OAuth sign-in endpoint at login.microsoftonline[.]com, with parameters that asked for a silent sign-in attempt against an Entra application that the attacker had registered as multi-tenant.

The image displays a message from the VOICEMAIL CENTER, indicating a new voicemail for the recipient, with instructions to download the attachment to listen to the message.
Figure 15. Rendered sample of voicemail notification from the nested EML

Because no active sign-in session could satisfy the silent request, Microsoft’s authentication service redirected the recipient to the destination the attacker had pre-registered on the application. That destination was a path on clickup-attachments[.]com, ClickUp’s public attachment host, and served a Windows batch file named Financial_report.bat. Because the link routed through Microsoft authentication infrastructure, both recipients and URL scanners saw a login.microsoftonline[.]com link.

The batch file ran a hidden PowerShell command that pulled installer.exe from pixeldrain[.]com, saved it under the user’s Temp directory, ran it with a silent flag, and deleted the dropper on exit. Rather than stealing credentials, the campaign ultimately resulted in silent malware execution on the user’s Windows device.

A scripted command line interface, specifically a batch file for a silent installation process, which includes downloading an installer, executing it, and cleaning up afterward.
Figure 16. Source code of Financial_report.bat

Mitigation and protection guidance

Microsoft recommends the following mitigations to reduce the impact of this threat. Check the recommendations card for the deployment status of monitored mitigations.

  • Review the recommended settings for Exchange Online Protection and Microsoft Defender for Office 365 to ensure your organization has established essential defenses and knows how to monitor and respond to threat activity.
  • Invest in user awareness training and phishing simulations. Attack simulation training in Microsoft Defender for Office 365, which also includes simulating phishing messages in Microsoft Teams, is one approach to running realistic attack scenarios in your organization.
  • Enable Zero-hour auto purge (ZAP) in Defender for Office 365 to quarantine sent mail in response to newly acquired threat intelligence and retroactively neutralize malicious phishing, spam, or malware messages that have already been delivered to mailboxes.
  • Responders could also manually check for and purge unwanted emails containing URLs and/or Subject fields that are similar, but not identical, to those of known bad messages. Investigate malicious email that was delivered in Microsoft 365 and use Threat Explorer to find and delete phishing emails.
  • Turn on Safe Links and Safe Attachments in Microsoft Defender for Office 365.
  • Enable network protection in Microsoft Defender for Endpoint.
  • Encourage users to use Microsoft Edge and other web browsers that support Microsoft Defender SmartScreen, which identifies and blocks malicious websites, including phishing sites, scam sites, and sites that host malware.
  • Enable password-less authentication methods (for example, Windows Hello, FIDO keys, or Microsoft Authenticator) for accounts that support password-less. For accounts that still require passwords, use authenticator apps like Microsoft Authenticator for MFA. Refer to this article for the different authentication methods and features.
  • Configure automatic attack disruption in Microsoft Defender XDR. Automatic attack disruption is designed to contain attacks in progress, limit the impact on an organization’s assets, and provide more time for security teams to remediate the attack fully.

Microsoft Defender detections

Microsoft Defender customers can refer to the list of applicable detections below. Microsoft Defender coordinates detection, prevention, investigation, and response across endpoints, identities, email, apps to provide integrated protection against attacks like the threat discussed in this blog.

Microsoft Defender for Endpoint

The following alert might indicate threat activity associated with this threat. The alert, however, can be triggered by unrelated threat activity.

  • Suspicious activity likely indicative of a connection to an adversary-in-the-middle (AiTM) phishing site

Microsoft Defender for Office 365

The following alerts might indicate threat activity associated with this threat. These alerts, however, can be triggered by unrelated threat activity.

  • A potentially malicious URL click was detected
  • A user clicked through to a potentially malicious URL
  • Suspicious email sending patterns detected
  • Email messages containing malicious URL removed after delivery
  • Email messages removed after delivery
  • Email reported by user as malware or phish

Microsoft Security Copilot

Microsoft Security Copilot is embedded in Microsoft Defender and provides security teams with AI-powered capabilities to summarize incidents, analyze files and scripts, summarize identities, use guided responses, and generate device summaries, hunting queries, and incident reports.

Customers can also deploy AI agents, including the following Microsoft Security Copilot agents, to perform security tasks efficiently:

Security Copilot is also available as a standalone experience where customers can perform specific security-related tasks, such as incident investigation, user analysis, and vulnerability impact assessment. In addition, Security Copilot offers developer scenarios that allow customers to build, test, publish, and integrate AI agents and plugins to meet unique security needs.

Threat intelligence reports

Microsoft Defender XDR customers can use the following Threat Analytics reports in the Defender portal (requires license for at least one Defender XDR product) to get the most up-to-date information about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide intelligence, protection information, and recommended actions to prevent, mitigate, or respond to associated threats found in customer environments.

Microsoft Defender XDR threat analytics

Microsoft Security Copilot customers can also use the Microsoft Security Copilot integration in Microsoft Defender Threat Intelligence, either in the Security Copilot standalone portal or in the embedded experience in the Microsoft Defender portal to get more information about this threat actor.

Indicators of compromise (IOCs)

IndicatorTypeDescriptionFirst seenLast seen
9i6pokerdepot[.]comDomainSending domain; DKIM-signed by the operator2026-06-152026-06-15
Customer.Service[@]9i6pokerdepot[.]comEmail addressCampaign sender address2026-06-152026-06-15
t90141296286.p.clickup-attachments[.]comDomainClickUp attachment subdomain hosting the stage 2 BAT dropper2026-06-152026-06-15
hxxps://t90141296286.p.clickup-attachments[.]com/t90141296286/fb39c3a9-3161-40ad-847b-0683e0409d6f/Financial_report.batURLStage 2 BAT dropper download URL2026-06-152026-06-15
hxxps://pixeldrain[.]com/api/file/3v92oJiLURLFinal installer payload download URL2026-06-152026-06-15
Re: Teams Archive Recording for {{DATE2}}.emlFile nameNested EML attachment template name; the literal {{DATE2}} indicates an unfilled per-recipient template token2026-06-152026-06-15
Financial_report.batFile nameStage 2 dropper batch file delivered from the OAuth error redirect2026-06-152026-06-15
ecajovna[.]skDomainDomain used to send campaign emails2026-06-012026-06-01
ilyff[.]comDomainReply-to domain used to receive victim responses2026-06-012026-06-01
j-gmails[.]comDomainReply-to domain used to receive victim responses2026-06-012026-06-01
x2mails[.]comDomainReply-to domain used to receive victim responses2026-06-012026-06-01
contact[@]ecajovna[.]skEmail addressAddress used to send campaign emails2026-06-012026-06-01
mail[@]ilyff[.]comEmail addressReply-to address2026-06-012026-06-01
me[@]j-gmails[.]comEmail addressReply-to address2026-06-012026-06-01
me[@]x2mails[.]comEmail addressReply-to address2026-06-012026-06-01
compliance-protectionoutlook[.]deDomainDomain hosting malicious campaign content2026-04-142026-04-16
acceptable-use-policy-calendly[.]deDomainDomain hosting malicious campaign content2026-04-142026-04-16
cocinternal[.]comDomain  Domain hosting sender email address2026-04-142026-04-16
gadellinet[.]comDomain  Domain hosting sender email address2026-04-142026-04-16
harteprn[.]comDomainDomain hosting sender email address2026-04-142026-04-16
cocpostmaster[@]cocinternal[.]cmEmail addressEmail address used to send campaign emails2026-04-142026-04-16
nationaladmin[@]gadellinet[.]comEmail addressEmail address used to send campaign emails2026-04-142026-04-16
nationalintegrity[@]harteprn[.]comEmail addressEmail address used to send campaign emails2026-04-142026-04-16
m365premiumcommunications[@]cocinternal[.]comEmail addressEmail address used to send campaign emails2026-04-142026-04-16
documentviewer[@]na[.]businesshellosign[.]deEmail addressEmail address used to send campaign emails2026-04-142026-04-16
5DB1ECBBB2C90C51D81BDA138D4300B90EA5EB2885CCE1BD921D692214AECBC6SHA-256File hash of campaign PDF attachment2026-04-142026-04-16
B5A3346082AC566B4494E6175F1CD9873B64ABE6C902DB49BD4E8088876C9EADSHA-256  File hash of campaign PDF attachment2026-04-142026-04-16
11420D6D693BF8B19195E6B98FEDD03B9BCBC770B6988BC64CB788BFABE1A49DSHA-256  File hash of campaign PDF attachment2026-04-142026-04-16

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The post Email threat landscape: Q2 2026 trends and insights appeared first on Microsoft Security Blog.

ConsentFix: a new ClickFix variation for compromising Microsoft 365 accounts

Cybercriminals are increasingly moving away from complex malware, relying instead on social engineering that exploits a common user habit: mindlessly clicking through endless digital rituals like CAPTCHAs, cookie consents, and authentication prompts. This habit is often targeted by various kinds of the ClickFix technique, which threat actors have been actively using lately. Researchers recently discovered a new variant of this technique, which they dubbed ConsentFix. It allows attackers to gain unauthorized access to Microsoft 365 accounts via OAuth — a highly popular vector right now — thereby completely bypassing the need to steal passwords. For organizations, these attacks present a severe risk of compromised corporate email, exposed documents, and breached cloud resources.

How ConsentFix works

Social engineering lies at the core of all ClickFix variations. Attackers prompt the user to follow a seemingly harmless set of instructions, which actually lead to the compromise of their device or account. In the case of ConsentFix, these instructions are designed to trick the user into granting the attacker access to their Microsoft 365 account.

The attack begins by making the user believe they must authenticate with their Microsoft account to access a specific page or document. To do this, cybercriminals usually send an email containing a link to a website typically imitating a popular file-sharing service. Attempting to access a specific document on this site prompts the user for verification, which can be obtained by following this sequence of actions:

  1. Clicking Verify with Microsoft.
  2. Signing in to the work account, at which point the attackers warn that multi-factor authentication (MFA) may be required.
  3. After being redirected to a new page, waiting until “localauth” appears in the address bar.
  4. Dragging the information icon ⓘ from the browser’s address bar into a drop zone on the page.

In practice, following these instructions causes the user to drag an URL containing a session OAuth token directly onto the attacker’s page. This token is exactly what grants the attackers access to the victim’s email and other Microsoft 365 services.

The potential fallout of a Microsoft 365 session compromise

At first glance, it might seem like attackers only gain access to a mailbox. In reality, the consequences can be significantly more severe. The attacker’s specific capabilities depend on the organization’s Microsoft 365 license, the services deployed, and the privilege level of the compromised account.

Even basic corporate Microsoft 365 subscriptions typically grant access to Outlook, Teams, OneDrive, and SharePoint, while more advanced tiers may include additional services and administrative tools.

Even compromised corporate email alone is a major breach. The attacker not only gains access to email archives that may contain confidential business intelligence, but also can send phishing messages or launch internal BEC attacks on behalf of the user.

Beyond email, attackers are highly likely to gain access to the victim’s Microsoft Teams account, providing them with even deeper insights and broader leverage for various scams. Access to OneDrive and SharePoint is equally dangerous: it allows attackers to exfiltrate corporate documents, upload malware into cloud storage, tamper with existing files, and more. Ultimately, this creates a launchpad for moving laterally within the corporate infrastructure.

Publicly available attack blueprints

According to a Bleeping Computer article, the mechanics of ConsentFix are no secret. Attackers share detailed implementation guides on cybercrime forums, offering not only ready-to-use code but also video tutorials demonstrating how to deploy the attack. They also actively trade tips on how they harvest intelligence on organizations and their employees via LinkedIn and other OSINT channels to craft highly convincing phishing messages.

Collectively, this significantly lowers the barrier to entry for novice cybercriminals. As these guides and turnkey tools continue to proliferate, ConsentFix attacks will likely become increasingly common. Consequently, organizations should immediately factor this technique into both their defense strategies and employee awareness training programs.

How to secure your corporate infrastructure

The emergence of this new ClickFix variation demonstrates that simply blocking a specific keyboard shortcut or an isolated risky action on employee devices is not enough. Clearly, attackers quickly adapt to these measures. Therefore, to protect an organization from these types of attacks, we recommend the following:

  • Be sure to deploy a robust security solution at the mail gateway level — this minimizes the likelihood of attackers successfully luring your employees to a page hosting the ConsentFix mechanism.
  • Conduct regular cybersecurity awareness training for employees to keep them ahead of the latest social engineering tactics. Our training platform, Kaspersky Automated Security Awareness Platform, can assist with this initiative.

ACR Stealer: Two observed intrusion chains amid increased threat activity

From late April 2026 to mid-June 2026, Microsoft Defender Experts observed increased ACR Stealer activity across customer environments. These campaigns are successfully using ClickFix lures to steal browser credentials, authentication tokens, and sensitive documents from enterprise environments. Successful compromise can expose browser credentials, session tokens, authentication artifacts, and sensitive enterprise data, potentially enabling account compromise, unauthorized access to cloud resources, and follow-on intrusion activity. Security teams should prioritize monitoring for ClickFix lures, suspicious WebDAV activity, obfuscated PowerShell execution, and attempts to access browser credential stores.

ACR Stealer is an information-stealing malware family reportedly offered through a malware-as-a-service (MaaS) model and associated with the rebranding of Amatera Stealer. During this period, two campaigns stand out, together appearing frequently in reviewed recent intrusions. Both begin the same way, with a ClickFix social engineering technique that tricks targets into running the threat actor’s command, but the intrusion chains that follow diverge in how they deliver payloads, establish execution, and evade detection.

The first campaign relies on WebDAV-delivered payloads, staged PowerShell, Python-based loaders and persistence, and, in some intrusions, blockchain-backed dead-drop command-and-control (C2) resolution. The second campaign takes a more fileless route, using MSHTA, obfuscated PowerShell, and steganography-assisted in-memory execution. Despite these differences, both campaigns ultimately pursue the same goal: stealing browser-stored credentials and other sensitive data for exfiltration.

These two campaigns represent some of the most prevalent ACR Stealer delivery campaigns observed by Defender Experts; however, they do not represent the full range of delivery methods used by this malware family. Attribution to ACR Stealer is based on the observed behavior and post-exploitation tradecraft, corroborated by open-source intelligence on the infrastructure associated with this malware family. Additional campaigns, infrastructure patterns, and execution chains are likely active, and organizations should treat the indicators and techniques described here as representative.

Microsoft Defender for Endpoint can help surface both campaigns through behavioral coverage for living-off-the-land execution, suspicious WebDAV and MSHTA activity, obfuscated PowerShell, scheduled-task persistence, in-memory payload execution, and browser credential theft. In this blog, we analyze both campaigns in detail, including their delivery mechanisms, post-exploitation tradecraft, indicators of compromise, hunting opportunities, and guidance to help defenders detect and disrupt related activity in their environments.

Campaign 1: WebDAV-based ClickFix with Python loaders and blockchain C2

Initial access

In this campaign, a ClickFix prompt, likely delivered through malvertising or SEO-manipulated search results, instructs the target user to run a command that launches cmd.exe. The command subsequently invokes rundll32.exe to load a DLL from a remote WebDAV share accessed over HTTPS. The WebDAV path commonly uses a GUID-based directory structure and filenames designed to resemble legitimate resources (for example, google.ct), enabling the activity to blend with expected network traffic and evade casual inspection.

We observed three variants of the initial execution command:

Variant 1: Direct rundll32 invocation

Variant 2: pushd-Mounted WebDAV Share

Variant 3: Headless and obfuscated pushd execution

Variants 2 and 3 are notable for their use of pushd, which transparently maps the remote WebDAV share to a temporary local drive prior to execution. This technique allows threat actors to execute remotely hosted content through what appears to be a local path, simplifying payload execution while reducing user awareness. In the more advanced variant, threat actors further enhance stealth by launching commands through conhost.exe –headless, suppressing visible console windows, and employing environment variable obfuscation with delayed variable expansion to conceal critical execution components such as pushd, rundll32, and the remote host name. Combined with minimized or headless execution, these techniques reduce user visibility, complicate static analysis and detection, and enable the infection chain to execute with minimal indication to the victim.

Execution, persistence, and evasion through process masquerading

Once rundll32.exe loads the DLL retrieved from the remote server, the malware establishes communication with threat actor-controlled infrastructure and executes a heavily obfuscated PowerShell script. The script employs excessive arithmetic no-ops, dead loops, fake control flow, and randomized variable names to hinder static analysis and evade signature-based detection.

The PowerShell script subsequently deploys another stage that functions as both a malware installer and a persistence mechanism. It:

  • Downloads a ZIP-packaged payload from a remote server and extracts it into a deceptive directory under %LocalAppData%\Temp (for example, LogiOptionsPlus).
  • Launches a Python script using a bundled pythonw.exe instance to avoid displaying a console window.
  • Removes previous deployments and terminates running instances before installation, effectively operating as an updater.
  • Establishes persistence through a hidden scheduled task disguised as a legitimate software update, ensuring execution at user sign-in.
  • Copies timestamps from a trusted Windows binary (notepad.exe) to the deployed files and clears PowerShell command history to reduce forensic visibility.
PowerShell loader downloads and executes a payload through a masqueraded scheduled task.

Python loader launching the stealer

The Python component serves as a heavily obfuscated loader designed to conceal its true functionality until runtime. It employs multiple layers of defense against static analysis, including dynamic API resolution, encoded string reconstruction, junk-data removal, character shifting, string reversal, Base64 decoding, and zlib decompression. These techniques ensure that the embedded payload remains unreadable in its static form and is reconstructed only during execution, significantly hindering signature-based detection and automated analysis.

Once decoded, the final-stage payload functions as an in-memory shellcode loader. It extracts an archive file masquerading as a legitimate application installer, reads a file from the archive, and injects the payload into a system process. The loader allocates executable memory using VirtualAlloc, copies the payload into the allocated memory region, and transfers execution through the Windows Fiber API (ConvertThreadToFiber, CreateFiber, and SwitchToFiber). This technique facilitates stealthy in-memory execution while minimizing artifacts written to disk.

Decoded Python shellcode loader using VirtualAlloc and Fiber-based execution.

Credential theft and data staging for exfiltration

The malware (injected code) aggressively harvests information from browser credential stores. It invokes Windows Data Protection API (DPAPI) routines to decrypt locally stored browser passwords, cookies, and authentication tokens. It also enumerates files across the system, targeting PDFs, Microsoft 365 documents, and data stored in enterprise-synchronized directories such as OneDrive and SharePoint. The collected data is subsequently archived, indicating preparation for exfiltration.

Blockchain dead-drop C2 resolution

A notable variation in this campaign is the use of blockchain services for C2 resolution, utilizing a technique known as EtherHiding. While most intrusions rely on more conventional C2 mechanisms, a subset deploys an additional secondary Python loader that leverages blockchain services as dead-drop resolvers. When this loader executes, it has been observed communicating with public blockchain RPC endpoints and third-party Web3 node infrastructure, likely querying data stored on a decentralized public ledger to retrieve follow-up payloads or a C2 address.

By externalizing C2 information to the blockchain, operators could dynamically update infrastructure without modifying or redeploying the malware, significantly complicating detection and takedown efforts. This behavior was observed across both variants of the campaign.

Campaign 2: MSHTA-initiated PowerShell chain with steganographic payload delivery

The second campaign takes a distinctly different approach to both delivery and execution. Where Campaign 1 relies on disk-based artifacts (Python runtime, scheduled tasks, and masquerading binaries), this campaign achieves its objectives almost entirely through fileless, in-memory execution, making it harder to detect through file-based scanning and forensic analysis.

Initial access through MSHTA and ClickFix

The execution chain begins when the victim, directed through malvertising or SEO-manipulated search results, encounters a ClickFix prompt that triggers a command spawning MSHTA to fetch and execute remote HTA content from an threat actor-controlled domain. The embedded VBScript loader abuses COM objects to decode and execute encoded PowerShell content.

VBScript loader using COM objects to decode and launch a PowerShell payload.

PowerShell downloader and obfuscation

The decoded PowerShell stage employs obfuscation techniques similar to those seen in Campaign 1: randomized variable names, arithmetic no-op operations, dead loops, misleading control flow, and custom encryption routines. Prior to contacting its next-stage infrastructure, the malware generates a victim-specific identifier and disables certificate validation. The retrieved content is executed directly in memory.

Steganography-based payload delivery

A notable technique in this campaign is the use of steganography to conceal malicious content inside a publicly hosted image. Instead of downloading a secondary script (as in Campaign 1), the malware retrieves a JPEG image from an image-hosting service.

Steganographic payload extraction from a downloaded image prior to decryption and execution.

Analysis of the script revealed custom routines that extract an embedded payload from image pixels, decrypt and decompress it, and execute it entirely in memory. The payload dynamically resolves APIs such as LoadLibrary, GetProcAddress, VirtualAlloc, CreateThread, and WaitForSingleObject at runtime to perform reflective shellcode execution. By combining steganography with in-memory execution, the malware minimizes on-disk artifacts and complicates both detection and analysis.

Credential theft, data collection, and exfiltration

Following execution, the malware accesses credential stores belonging to Chromium-based browsers, including Google Chrome and Microsoft Edge, specifically the Login Data and Web Data databases, alongside Windows DPAPI decryption activity. This behavior indicates attempts to recover stored browser credentials, session cookies, authentication tokens, and other sensitive user information.

The malware also enumerates and accesses multiple high-value PDF documents across Desktop and Downloads locations, suggesting targeted collection of potentially sensitive files. The combination of browser credential harvesting and systematic document access points to an information-stealing objective focused on staging credentials and valuable user data for exfiltration.

Mitigation and protection guidance

Microsoft recommends the following mitigations to reduce the impact of ClickFix lures, script-based payload delivery, credential theft, and post-compromise activity.

  • Educate users to recognize ClickFix-style prompts, fake verification checks, and paste-and-run instructions as malicious, especially when they invoke command interpreters or script hosts such as cmd.exe, PowerShell, rundll32.exe, or mshta.exe.
  • Reduce exposure to malvertising, SEO poisoning, and other web-based delivery chains by enforcing web filtering, blocking low-reputation or newly observed domains, and limiting access to remote content sources that are not required for business operations.
  • Use application control and attack surface reduction rules to restrict PowerShell, Python, mshta.exe, rundll32.exe, and similar tools from launching untrusted or internet-delivered content, particularly from user-writable directories such as Downloads, Temp, and %LocalAppData%.
  • Monitor for suspicious persistence and defense-evasion behavior, including scheduled tasks masquerading as software updates, timestomping, PowerShell history clearing, and execution chains that progress from remote content retrieval into PowerShell, Python, or shellcode-loading behavior.
  • Investigate abnormal access to Chromium-based browser databases, DPAPI-related decryption activity, staged collection of Microsoft 365 documents or PDFs, and compression activity that may indicate credential theft or data staging for exfiltration.
  • If compromise is suspected, isolate affected devices, rotate exposed credentials, revoke potentially compromised tokens, review persistence mechanisms, and investigate outbound connections to remote shares, image-hosting services, or other infrastructure used to resolve or retrieve follow-on payloads.
  • Harden endpoints against credential theft by reducing reliance on browser-stored credentials, enforcing multifactor authentication and conditional access, and reviewing how privileged accounts access sensitive applications and synchronized enterprise data.
  • Turn on cloud-delivered protection and behavior-based detections to help identify rapidly evolving threats, suspicious script execution, in-memory payload delivery, abuse of browser credential stores, and unusual child-process activity.
  • Run endpoint detection and response (EDR) in block mode and enable automated investigation and remediation so post-breach detections are contained, and malicious artifacts can be removed with minimal delay.
  • Harden PowerShell by enforcing appropriate execution policies, turning on script block logging, module logging, and transcription, and monitoring this telemetry for signs of malicious script activity.
  • Turn on tamper protection and prevent local administrators from weakening antivirus protection through local policy or exclusion changes.

Microsoft Defender XDR detections

Microsoft Defender XDR customers can refer to the list of applicable detections below. Microsoft Defender XDR coordinates detection, prevention, investigation, and response across endpoints, identities, email, and apps to provide integrated protection against attacks like the threat discussed in this blog. 

TacticObserved ActivityMicrosoft Defender Coverage
Execution– Suspicious MSHTA launch through ClickFix execution
– Rundll32 loads remote WebDAV DLL
– COM objects launch in-memory PowerShell
Microsoft Defender for Endpoint
– Use of living-off-the-land binary to run malicious code
– Obfuscated command line was launched
– Suspicious process executed PowerShell command
– Suspicious process launch by Rundll32.exe

Microsoft Defender for Antivirus
Behavior:Win32/Interhta.Int
PersistencePowerShell creates Scheduled task, masquerading as a software updateMicrosoft Defender for Endpoint
– Suspicious Scheduled Task Process Launched  
– Suspicious scheduled task
Stealth/Defense Evasion– Fiber-API in-memory shellcode execution
– Reflective shellcode via CreateThread
Microsoft Defender for Endpoint
Possible process hollowing
Credential AccessCollects browser credentials, cookies, and tokens while enumerating files for exfiltrationMicrosoft Defender for Endpoint
– Information stealing malware activity  
– Suspicious DPAPI activity
– Possible theft of passwords and other sensitive web browser information

Microsoft Security Copilot

Microsoft Security Copilot is embedded in Microsoft Defender and provides security teams with AI-powered capabilities to summarize incidents, analyze files and scripts, summarize identities, use guided responses, and generate device summaries, hunting queries, and incident reports.

Customers can also deploy AI agents, including the following Microsoft Security Copilot agents, to perform security tasks efficiently:

Security Copilot is also available as a standalone experience where customers can perform specific security-related tasks, such as incident investigation, user analysis, and vulnerability impact assessment. In addition, Security Copilot offers developer scenarios that allow customers to build, test, publish, and integrate AI agents and plugins to meet unique security needs.

Threat intelligence reports

Microsoft Defender XDR customers can use the following threat analytics reports in the Defender portal (requires license for at least one Defender XDR product) to get current information available in the Defender portal about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide the intelligence, protection information, and recommended actions to help prevent, mitigate, or respond to associated threats found in customer environments:

Microsoft Security Copilot customers can also use the Microsoft Security Copilot integration in Microsoft Defender Threat Intelligence, either in the Security Copilot standalone portal or in the embedded experience in the Microsoft Defender portal to get more information about this threat actor.

Advanced hunting queries

Microsoft Defender XDR customers can run the following advance hunting queries to find related activity in their networks:

Run the query below to identify suspicious commands executed through ClickFix-based activity observed while delivering this stealer

DeviceRegistryEvents
| where RegistryKey has "RunMRU"
| where (RegistryValueData has_all ("rundll32", "@ssl", " /c ", " start ") and (RegistryValueData matches regex @"\\\\[^\\]+@ssl\\[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}\\\w+\.\w+,#1" or
RegistryValueData matches regex @"(?i)pushd \\\\[^\\]+@ssl\\[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12} ")) 
or RegistryValueData has_all ("@ssl", " /c ", "conhost --headless ") and RegistryValueData contains "rundll32"

Run the query below to identify scheduled task creation used for persistence by a malicious PowerShell script

DeviceProcessEvents
| where InitiatingProcessFileName =~ "powershell.exe"
| where InitiatingProcessCommandLine has_all ("-Command", "powershell")
| where ProcessCommandLine has_all ("schtasks", " /run /tn ", " Autoupdate ") and ProcessCommandLine matches regex "[0-9]{8}"

Run the query below to identify suspicious MSHTA launch through PowerShell

DeviceProcessEvents
| where InitiatingProcessParentFileName has "explorer.exe"
| where InitiatingProcessFileName =~ "powershell.exe" and InitiatingProcessCommandLine in~ ('"PowerShell.exe" ', '"PowerShell.exe"')
| where ProcessCommandLine has_all ('"mshta.exe" https://') and ProcessCommandLine matches regex "/[0-9]{7}"

MITRE ATT&CK techniques observed

The following mapping summarizes the primary tactics and techniques observed across the two ACR Stealer intrusion chains. The mapping is intended to help defenders align observed behaviors with existing detection coverage, response playbooks, and hunting priorities.

TacticTechniqueObserved behavior
Initial AccessDrive-by Compromise; User ExecutionClickFix lure prompts command execution.
ExecutionCommand and Scripting Interpreter: Windows Command Shell; PowerShell; Pythoncmd.exe, PowerShell, and pythonw.exe launch staged payloads.
ExecutionSystem Binary Proxy Execution: Rundll32; MshtaRundll32 loads WebDAV DLLs; mshta.exe runs remote HTA content.
PersistenceScheduled Task/Job: Scheduled TaskHidden scheduled task maintains user-logon execution.
Defense EvasionObfuscated Files or Information; Masquerading; Indicator Removal: Clear Command HistoryObfuscation, timestomping, history clearing, and masquerading.
Defense EvasionObfuscated Files or Information: SteganographyJPEG pixel data hides the encrypted payload.
Defense Evasion / ExecutionReflective Code Loading; Process InjectionIn-memory shellcode execution via runtime API resolution.
Credential AccessCredentials from Web BrowsersBrowser stores and DPAPI activity used to recover credentials and tokens.
CollectionData from Local System; Data StagedPDFs, Office files, and synced enterprise data are staged.
Command and ControlWeb Service; Dead Drop ResolverInfrastructure and blockchain RPC endpoints resolve payload or C2 data.

Indicators of compromise (IOC)

Campaign 1
IndicatorDescription
looksta[.]icuC2 domain
contrite.quirksturdy[.]icuC2 domain
ux.strainedeasily[.]icuC2 domain
cpppemwjewjoiwejow[.]saleC2 domain
breaksd.wifihot[.]icuC2 domain
walter.filloco[.]icuC2 domain
fast.raidher[.]icuC2 domain
apigrokcloud[.]icuC2 domain
Campaign 2
enhanceblabber[.]ccC2 domain
deep-harborio[.]com1st Stage payload hosting site
auramatrixa[.]com1st Stage payload hosting site
zealpraxis[.]com1st Stage payload hosting site
prism-vertex[.]com1st Stage payload hosting site
prism-matrixs[.]com1st Stage payload hosting site
proton-network[.]com1st Stage payload hosting site
creativecommunityinfo[.]artPayload hosting site

References

Learn more

For the latest security research from the Microsoft Threat Intelligence community, check out the Microsoft Threat Intelligence Blog.

To get notified about new publications and to join discussions on social media, follow us on LinkedInX (formerly Twitter), and Bluesky.

To hear stories and insights from the Microsoft Threat Intelligence community about the ever-evolving threat landscape, listen to the Microsoft Threat Intelligence podcast.

Review our documentation to learn more about our real-time protection capabilities and see how to enable them within your organization.   

The post ACR Stealer: Two observed intrusion chains amid increased threat activity appeared first on Microsoft Security Blog.

Detection engineering in the AI era

9 July 2026 at 09:41

The conversation around AI-powered threats has focused heavily on the attacker side. What models can do, what vulnerabilities they can find, how fast they can chain exploits together. But the more important question for security practitioners is simpler and harder. Is your detection posture ready for what’s already happening?

AI has lowered the barrier to entry for sophisticated attacks. Threat actors don’t need to be experts to leverage LLMs for obfuscation, exploit development, or chaining attack steps that previously required deep manual skill. The speed and volume of attacks is increasing as a result. Detection engineering is part of how defenders respond. And most organizations are further behind than they realize, especially because many detection engineering programs live in their own siloed “ivory tower”, detached from the realities of what SOC analysts are handling. 

At Intezer, AI-powered detection engineering runs as part of a closed loop with automated, forensic triage and investigation. Every alert investigated across the environment feeds new signal back into detection logic, so coverage improves continuously instead of drifting between quarterly tuning cycles. Detection working in concert with triage and investigation is what a fully optimized security environment looks like against AI-powered attackers.

In this article, we’ll focus on how to improve detection engineering practices in general. 

Why your current detection posture isn’t keeping pace

The fundamental problem is that most detection programs were built for a world where attack volume was bounded by attacker expertise. That constraint is being removed. LLM-augmented attacks can move faster, produce more permutations, and adapt more readily to your environment than traditional campaigns. A detection posture built on static indicators and periodic tuning cycles can’t keep up.

There are three places this shows up in practice.

Covering one sub-technique doesn’t cover the technique

First, most organizations are only covering technique-level MITRE ATT&CK mappings, not sub-techniques. When you claim T1059 is covered because you have a rule for T1059.001, you’re exposing yourself to real risk hiding beneath that coverage number. Sub-techniques carry distinct behaviors that may exist in your environment and go completely undetected. High-level coverage scores look good in reports and obscure what’s actually happening. The risk lives at the sub-technique level.

IOCs are brittle indicators 

Second, IOC-based detections are becoming a liability at scale. IP addresses, file hashes, domains are valuable in incident response but brittle as primary detection logic. Their half-life is short, adversaries burn them readily, and maintaining a large list of active IOCs creates noise without proportionate signal. Organizations that lead with IOCs end up toggling rules on and off constantly, adding friction without improving coverage. The maintenance cost compounds without a meaningful security return.

Pulling logs is not the same as pulling useful logs

Third, telemetry that looks healthy often isn’t. A Windows Event ID 4688 without command-line logging enabled is an example. You’re paying to ingest it, it shows up in your coverage maps, but it provides no actionable data when something fires. Unmapped or broken telemetry creates the appearance of coverage where none actually exists. Before you write a new rule, validate that the data it depends on actually contains what you think it does.

What behavioral detection actually means in practice

Behavioral detections are built around what attackers do across a campaign, not what artifacts they happened to leave behind in a specific incident. Techniques, sequences, tool patterns, execution chains persist across campaigns, across threat actors, and even across malware families. A behavioral detection written well today has a much longer useful life than any IOC-based rule.

The shift to behavioral detection isn’t just a philosophy, it requires specific changes to how rules are built and maintained.

Score based detection

Score-based detection logic is one of the most underused approaches in enterprise SIEMs. If you’re running Splunk, Sumo Logic, or Cortex XDR, score-based rules let you assign weighted values to individual signals and alert when combinations cross a threshold. Individual signals that are weak in isolation, a process executing from an unusual path, a network connection to an uncommon destination, a scheduled task created outside business hours, become meaningful together. Noise goes down. True positive rate goes up. And the system stays tunable as your environment changes.

Permutation testing

Permutation testing is the other discipline most detection programs skip. LLMs make it straightforward to generate attack variants at volume. Defenders should be doing the same before releasing rules. If a detection rule only catches one specific implementation of a technique, an attacker using a slightly different toolchain or execution order will evade it. Testing rules against a range of permutations before production deployment closes gaps that post-deployment tuning will miss.

The detection engineering cycle has to get faster

The traditional cycle, write a rule, deploy it, wait for something to fire, tune reactively when it generates too many false positives, is too slow for the current threat environment. By the time you’ve finished tuning a rule for last quarter’s threat, new attack patterns are already in the wild.

The cycle needs to compress at every stage. Prototype rules should be tested in isolated environments before they reach production. Sandboxes and virtual machines can be spun up quickly in the same pipeline as rule development, giving you a controlled validation environment. Rules that are tuned before deployment don’t flood the SOC on their first day, and analysts who aren’t buried in false positives from new rules are analysts who can actually investigate real threats.

Continuous monitoring closes the loop. Every alert that fires, every verdict and every outcome feeds information back into the detection posture. Which rules are generating signal? Which ones are generating noise? Where are the coverage gaps that no existing rule addresses? Without this feedback loop, detection engineering becomes a periodic exercise rather than a continuously improving system.

A well integrated feedback loop investigates every single alert a detection creates, resolves false positives from critically important detections while continuously tuning the behavioral model to secure your organization and security detection pipeline.

Coverage benchmarks worth using

Coverage benchmarks help set realistic expectations and give teams a concrete target. Based on what we see across enterprise environments:

  • Less than 30% MITRE ATT&CK coverage is immature. Organizations in this range typically have out-of-the-box rules, minimal customization, and significant gaps across Initial Access, Execution, and Lateral Movement.
  • 30 to 45% represents a decent in-house SOC. Rules exist, there’s some customization, but detection engineering is not a dedicated discipline and tuning is reactive.
  • 45 to 60% is strong. Dedicated attention to detection posture, some behavioral logic, and active management of the detection lifecycle.
  • 60 to 70% is top-tier. Behavioral detection is primary, coverage is continuously maintained, and the feedback loop between investigation and detection is functioning.

Anything above 70% is usually inflated. Scores at this level typically reflect mapping sprawl across multiple MITRE versions, technique-level claims that obscure sub-technique gaps, or rules that are mapped but broken. Validate the underlying data before trusting the number.

The goal isn’t 100% coverage. That number isn’t achievable or meaningful. The goal is systematic, maintainable coverage of the techniques most relevant to your environment and your crown jewels, with the sub-technique depth to catch how those techniques are actually executed.

How AI changes things for attackers and defenders

Mythos focused attention on a specific capability and that is autonomous chaining of exploit steps that previously required human guidance at each stage. A skilled researcher can still walk an LLM through finding a vulnerability, reaching exploit code, and overtaking an instruction pointer, but that process requires human direction at each transition. What makes autonomous chaining meaningful is that it removes the human from the loop on the attacker side.

The detection engineering response isn’t a new category of rule. It’s the same disciplines applied with more rigor and at higher speed. Attackers using LLMs are still executing against endpoints, still writing to disk or running in memory, still making network connections, still creating processes. The behaviors are recognizable. What changes is the volume of variants and the speed at which new campaigns emerge.

Score-based logic handles volume well because it doesn’t require a rule per variant. Permutation testing handles new variants better than reactive tuning because gaps are found before deployment rather than after. Behavioral coverage handles campaign evolution better than IOC maintenance because the underlying techniques persist even as the tooling changes.

This is where an integrated model matters most. AI-powered detection engineering delivers the most value when it doesn’t operate in isolation, and at Intezer it runs on the same loop as automated triage and investigation. The platform investigates 100% of alerts across endpoint, identity, cloud, network, and SIEM, and every verdict feeds directly back into detection, surfacing noisy rules, broken telemetry, and coverage gaps as they happen rather than at the next review. Detection, triage, and investigation reinforcing one another is what produces a fully optimized security environment, one that keeps pace as attacker AI accelerates.

The organizations that fare best against AI-powered threats will be the ones that already had a functioning detection engineering program, one built on behavioral logic, continuous feedback, and validated telemetry, before the threat landscape changed. Catching up under pressure is possible, but it’s harder and slower than building the discipline now.

The attacker’s AI is getting faster. The detection engineering cycle should be too.

Learn more about Intezer’s AI-powered detection engineering.

The post Detection engineering in the AI era appeared first on Intezer.

Cardiac patients&#8217; medical data stolen and held to ransom

16 June 2026 at 14:49

Cardiac monitoring provider iRhythm has been hit by a data theft followed by an extortion attempt.

In a filing with the Securities and Exchange Commission (SEC), iRhythm revealed it was contacted by someone on June 9 who claimed to have stolen sensitive information, including proprietary data, patient PHI, and other personal information. That person demanded payment in exchange for not publishing the data.

iRhythm provides ambulatory cardiac monitoring and analysis (for example using the Zio patch) and has reportedly processed over two billion hours of heartbeat data from more than twelve million patients.

In the filing, the company said the data was obtained through social engineering and is from “certain third-party-hosted business applications”, without revealing any further details about the amount of data.

On its own website, iRhythm also doesn’t disclose much about the nature of the stolen data, but does seem to imply no financial data was affected:

“We have not identified any impact to our products, our clinical or medical device systems, our connections to customers, our manufacturing and distribution operations, patient safety, or our ability to meet patient needs. In addition, we do not store or retain individual financial account information or payment card information. 

 As we actively investigate, we will notify individuals affected by this incident in accordance with applicable law and take steps as needed to protect and remediate the impact to them.“

However, the SEC filing adds that iRhythm determined that the incident is significant, “in light of the volume of the potentially affected data.” Together with the extortionist’s claims that they have patients’ medical data, that makes the breach one worth noting if you have used iRhythm’s services.

Even without payment data, healthcare breaches have serious downstream effects:

  • Attackers can craft highly convincing emails, texts, or calls that reference specific procedures or monitoring episodes (for example, “about your recent Zio patch recording”) to trick patients into sharing more data or paying fake bills.
  • The breached data can be used to create a fake identity, insurance fraud, or medical identity theft.
  • Exposure of cardiac and other health‑related information can be deeply sensitive and may have employment/insurance ramifications, especially if data is posted publicly or sold to data brokers.

Healthcare breach data tends to circulate for years, and victims may face sporadic fraud and phishing attempts long after the headlines fade.

How to stay safe

If you’ve used iRhythm’s services, keep an eye on your post, email, and patient portals for official breach notifications from iRhythm or your healthcare provider.

In the US, breaches of protected health information that meet certain criteria must be reported to patients and regulators. iRhythm has promised to “notify individuals affected by this incident in accordance with applicable law and take steps as needed to protect and remediate the impact to them.”

To stay out of the hands of phishers and scammers:

  • When you receive a communication about the data breach, verify through other channels that it really came from iRhythm. Go directly to iRhythm’s official website or patient portal, or call a known phone number to confirm the communication is genuine.
  • Be extra suspicious of emails or texts that claim to offer compensation, refunds, or other financial consequences related to this incident.
  • Change passwords for your iRhythm‑linked portals and your cardiology or hospital patient portals, especially if you reused those passwords elsewhere.
  • Log into your health insurer’s portal and check claims on a regular basis.
  • If you see anything suspicious, report it immediately to your insurer and provider and ask them to flag your account for possible identity theft.
  • Do not provide personal or financial information over the phone just because the caller knows details about you which they may have obtained from the stolen data.

Let’s face it, an incognito window can only do so much. 
 
Breaches, dark web trading, credit fraud. Malwarebytes Identity Theft Protection monitors for all of it, alerts you fast, and comes with identity theft insurance. 

Cardiac patients&#8217; medical data stolen and held to ransom

16 June 2026 at 14:49

Cardiac monitoring provider iRhythm has been hit by a data theft followed by an extortion attempt.

In a filing with the Securities and Exchange Commission (SEC), iRhythm revealed it was contacted by someone on June 9 who claimed to have stolen sensitive information, including proprietary data, patient PHI, and other personal information. That person demanded payment in exchange for not publishing the data.

iRhythm provides ambulatory cardiac monitoring and analysis (for example using the Zio patch) and has reportedly processed over two billion hours of heartbeat data from more than twelve million patients.

In the filing, the company said the data was obtained through social engineering and is from “certain third-party-hosted business applications”, without revealing any further details about the amount of data.

On its own website, iRhythm also doesn’t disclose much about the nature of the stolen data, but does seem to imply no financial data was affected:

“We have not identified any impact to our products, our clinical or medical device systems, our connections to customers, our manufacturing and distribution operations, patient safety, or our ability to meet patient needs. In addition, we do not store or retain individual financial account information or payment card information. 

 As we actively investigate, we will notify individuals affected by this incident in accordance with applicable law and take steps as needed to protect and remediate the impact to them.“

However, the SEC filing adds that iRhythm determined that the incident is significant, “in light of the volume of the potentially affected data.” Together with the extortionist’s claims that they have patients’ medical data, that makes the breach one worth noting if you have used iRhythm’s services.

Even without payment data, healthcare breaches have serious downstream effects:

  • Attackers can craft highly convincing emails, texts, or calls that reference specific procedures or monitoring episodes (for example, “about your recent Zio patch recording”) to trick patients into sharing more data or paying fake bills.
  • The breached data can be used to create a fake identity, insurance fraud, or medical identity theft.
  • Exposure of cardiac and other health‑related information can be deeply sensitive and may have employment/insurance ramifications, especially if data is posted publicly or sold to data brokers.

Healthcare breach data tends to circulate for years, and victims may face sporadic fraud and phishing attempts long after the headlines fade.

How to stay safe

If you’ve used iRhythm’s services, keep an eye on your post, email, and patient portals for official breach notifications from iRhythm or your healthcare provider.

In the US, breaches of protected health information that meet certain criteria must be reported to patients and regulators. iRhythm has promised to “notify individuals affected by this incident in accordance with applicable law and take steps as needed to protect and remediate the impact to them.”

To stay out of the hands of phishers and scammers:

  • When you receive a communication about the data breach, verify through other channels that it really came from iRhythm. Go directly to iRhythm’s official website or patient portal, or call a known phone number to confirm the communication is genuine.
  • Be extra suspicious of emails or texts that claim to offer compensation, refunds, or other financial consequences related to this incident.
  • Change passwords for your iRhythm‑linked portals and your cardiology or hospital patient portals, especially if you reused those passwords elsewhere.
  • Log into your health insurer’s portal and check claims on a regular basis.
  • If you see anything suspicious, report it immediately to your insurer and provider and ask them to flag your account for possible identity theft.
  • Do not provide personal or financial information over the phone just because the caller knows details about you which they may have obtained from the stolen data.

Let’s face it, an incognito window can only do so much. 
 
Breaches, dark web trading, credit fraud. Malwarebytes Identity Theft Protection monitors for all of it, alerts you fast, and comes with identity theft insurance. 

The Art of the Badge: A Hard Truth About Physical Security

He walked into the lobby with a fake badge clipped to his shirt. He had bought it online the week before. It was not perfect, and it did not need to be. From a few feet away, it looked close enough: a logo, a name, a photo, and a lanyard. The kind of thing most people glance at for half a second before their brain decides, “Looks fine.”

The post The Art of the Badge: A Hard Truth About Physical Security appeared first on Black Hills Information Security, Inc..

When “Hi, This Is IT” Comes Through Microsoft Teams

9 June 2026 at 01:00

Attackers are increasingly targeting collaboration platforms like Microsoft Teams. Learn the risks and key steps to strengthen your organization's security.

The post When “Hi, This Is IT” Comes Through Microsoft Teams appeared first on Unit 42.

Fast16 Malware

30 April 2026 at 12:22

Researchers have reverse-engineered a piece of malware named Fast16. It’s almost certainly state-sponsored, probably US in origin, and was deployed against Iran years before Stuxnet:

“…the Fast16 malware was designed to carry out the most subtle form of sabotage ever seen in an in-the-wild malware tool: By automatically spreading across networks and then silently manipulating computation processes in certain software applications that perform high-precision mathematical calculations and simulate physical phenomena, Fast16 can alter the results of those programs to cause failures that range from faulty research results to catastrophic damage to real-world equipment.”

Another news article.

Lots of interesting details at the links.

Targeting developers: real-world cases, tactics, and defense strategies | Kaspersky official blog

22 April 2026 at 18:11

Lately, hackers have been turning up the heat on software developers. On the surface, this might seem like a puzzling move — why go after someone who’s literally paid to understand tech when there are plenty of less-savvy targets in the office? As it turns out, compromising a developer’s machine offers a much bigger payoff for an attacker.

Why developers are such high-value targets

For starters, compromising a coder’s workstation can give attackers a direct line to source code, credentials, authentication tokens, or even the entire development infrastructure. If the company builds software for others, a hijacked dev environment allows attackers to launch a massive supply chain attack, using the company’s products to infect its customer base. If the developer works on internal services, their machine becomes a perfect beachhead for lateral movement, allowing hackers to spread deeper into the corporate network.

Even when attackers are purely chasing cryptocurrency (and let’s face it, tech pros are much more likely to hold crypto than the average person), the malware used in these hits doesn’t just swap out wallet addresses; it vacuums up every scrap of valuable data it can find — especially those login credentials and session tokens. Even if the original attackers don’t care about corporate access, they can easily flip those credentials to initial access brokers or more specialized threat actors on the dark web.

Why developers are sitting ducks

In practice, developers aren’t nearly as good at understanding cyberthreats and spotting social engineering as they think they are. This misconception is a big reason why they often fall prey to cybercriminals. Professional expertise can often create a false sense of digital invincibility. This often leads technical professionals to cut corners on security protocols, bypass restrictions set by the security team, or even disable security software on their corporate machines when it gets in the way of their workflow. That mindset, combined with a job that requires them to constantly download and run third-party code, makes them sitting ducks for cyberattackers.

Attack vectors targeting developers

Once an attacker sets their sights on a software engineer, their go-to move is usually finding a way to slip malicious code onto the machine. But that’s just the tip of the iceberg — hackers are also masters at rebranding classic, battle-tested tactics.

Compromising open-source packages

One of the most common ways to hit a developer is by poisoning open-source software. We’ve seen a flood of these attacks over the past year. A prime example hit in March 2026, when attackers managed to inject malicious code into LiteLLM, a popular Python library hosted in the PyPI repository. Because this library acts as a versatile gateway for connecting various AI agents, it’s baked into a massive number of projects. These trojanized versions of LiteLLM delivered scripts designed to hunt for credentials across the victim’s system. Once stolen, that data serves as a skeleton key for attackers to infiltrate any company that was unlucky enough to download the infected packages.

Malware hidden in technical assignments

Every so often, attackers post enticing job openings for developers, complete with take-home test assignments that are laced with malicious code. For instance, in late February 2026, malicious actors pushed out web application projects built on Next.js via several malicious repositories, framing them as coding tests. Once a developer cloned the repo and fired up the project locally, a script would trigger automatically to download and install a backdoor. The attackers gained full remote access to the developer’s machine.

Fake development tools

Recently, our experts described an attack where hackers used paid search-engine ads to push malware disguised as popular AI tools. One of the primary baits was Claude Code, an AI coding assistant. This campaign specifically targeted developers looking for a way to use AI-assistants under the radar, without getting the green light from their company’s infosec team. The ads directed users to a malicious site that perfectly mimicked the official Claude Code documentation. It even included “installation instructions”, which prompted the user to copy and run a command. In reality, running that command installed an infostealer that harvested credentials and shuttled them off to a remote server.

Social engineering tactics

That said, attackers often stick to the basics when trying to plant malware. A recent investigation into a compromised npm package — Axios — revealed that hackers had gained access to a maintainer’s system using a shockingly simple “outdated software” ruse. The attackers reached out to the Axios repository maintainer while posing as the founder of a well-known company. After some back-and-forth, they invited him to a video interview. When the developer tried to join the meeting on what looked like Microsoft Teams, he hit a fake notification claiming his software was out of date and needed an immediate update. That “update” was actually a Remote Access Trojan, giving the attackers access to his machine.

Niche spam

Sometimes, even a blast of fake notifications does the trick, especially when it’s tailored to the audience. For example, just recently, attackers were caught posting fake alerts in the Discussions tabs of various GitHub projects, claiming there was a critical vulnerability in Visual Studio Code that required an immediate update. Because developers subscribed to those discussions received these alerts directly via email, the notifications looked like legitimate security warnings. Of course, the link in the message didn’t lead to an official patch; it pointed to a “fixed” version of VS Code that was actually laced with malware.

How to safeguard an organization

To minimize the risk of a breach, companies should lean into the following best practices:

Tax Refund Fraud in 2026: How Threat Actors Exploit Identity, Verification, and Cash-Out Channels

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Tax Refund Fraud in 2026: How Threat Actors Exploit Identity, Verification, and Cash-Out Channels

In this post, we examine how threat actors are executing tax refund fraud schemes, from sourcing identity data to bypassing verification and cashing out fraudulent returns, and what these patterns reveal about evolving fraud ecosystems.

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April 9, 2026

Tax refund fraud remains a persistent and evolving threat within cybercrime and fraud communities. Threat actors actively advertise and refine schemes designed to file fraudulent returns and intercept refund payments from legitimate taxpayers.

Across illicit forums, Telegram channels, and marketplaces, discussions point to a structured ecosystem built around identity data, social engineering, verification bypass, and increasingly sophisticated cash-out methods.

For intelligence teams, these conversations provide insight into how fraud operations are scaling and where defenses are being tested and adapted.

The Structure of Modern Tax Refund Fraud Schemes

At a high level, most tax refund fraud schemes follow a consistent model: obtain identity data, file a fraudulent return, bypass verification, and extract funds.

Flashpoint analysis shows that threat actors focus on several key stages:

  • Sourcing victims or identity “fullz” (complete PII packages)
  • Obtaining or bypassing identity and return verification
  • Leveraging social engineering to support fraud workflows
  • Using tutorials and shared methods to maximize refund amounts
  • Converting refunds into cash or cryptocurrency

These stages are not isolated. They are supported by overlapping communities that specialize in identity theft, financial fraud, and account access.

Identity Data as the Foundation of Fraud

The success of tax refund fraud depends heavily on access to high-quality identity data.

Threat actors typically rely on “fullz,” which include a victim’s name, date of birth, address, and Social Security number. In some cases, fraudsters also recruit “clients” or “tax heads” — individuals who knowingly or unknowingly provide accurate tax documents and assist in bypassing verification steps.

This distinction is important. While fullz can be purchased or harvested at scale, clients often provide more reliable and current information, increasing the likelihood that a fraudulent return will be accepted.

A threat actor shares a screenshot of a text exchange with a client in which they obtain access to their TurboTax account and tax forms accessible through the account. (Source: Telegram, Flashpoint Collections).

Threat actors also seek additional data points to legitimize filings, including:

  • Identity Protection (IP) PINs
  • Adjusted Gross Income (AGI) from previous tax years
  • Access to tax preparation accounts or IRS records

These elements are frequently obtained through compromised accounts, social engineering, or access to verified identity platforms.

Verification Bypass as a Critical Enabler

Filing a fraudulent return is only part of the process. Successfully passing identity and return verification is often the deciding factor.

Threat actors place significant emphasis on accessing or creating verified accounts tied to identity systems used by government agencies. These accounts allow fraudsters to:

  • Retrieve tax transcripts and historical data
  • Respond to IRS verification requests
  • Validate identity during filing and follow-up processes

In many cases, fraudsters rely on social engineering to obtain this access. Common approaches include:

  • Creating fake job postings or tax preparation services to collect documents
  • Running romance or employment scams to gather personal information
  • Coercing victims into creating or sharing verified accounts

Threat actors also prepare for additional verification steps, such as responding to IRS letters or completing phone and in-person identity checks. These workflows often involve scripts, impersonation tactics, and coordination with cooperating “clients.”

Fraud Tactics Are Increasingly Systematic

Beyond basic filing, threat actors share detailed tutorials and playbooks designed to maximize refunds and improve success rates.

These often include:

  • Using real or falsified income data to inflate returns
  • Targeting specific tax credits, such as the Child Tax Credit (CTC), Earned Income Tax Credit (EITC), or Employer Retention Credit (ERC)
  • Claiming dependents or benefits that increase refund amounts
  • Adapting methods based on state-specific programs or eligibility requirements

A notable development is the use of fraudulent income submission schemes, where threat actors pre-populate tax records with inflated income and withholding data before filing a return.

This process typically involves:

  1. Submitting false wage data to the IRS or Social Security Administration using employer identifiers
  2. Waiting for the data to appear on official tax transcripts
  3. Filing a return that matches the fabricated figures

By aligning submitted data with filed returns, fraudsters increase the likelihood that filings will appear legitimate during verification.

Social Engineering Extends Beyond Victims

Social engineering plays a central role throughout the fraud lifecycle—and not just at the initial data collection stage.

Threat actors also target:

  • IRS representatives, attempting to verify fraudulent returns over the phone
  • Clients, persuading them to attend verification appointments or share official correspondence
  • Government offices, including outreach to congressional staff to resolve refund holds

In some cases, fraudsters use AI-generated communications to scale these efforts, including drafting messages designed to appear legitimate and urgent.

These tactics highlight how fraud operations extend into real-world processes and human interactions, not just digital systems.

Cash-Out Methods Continue to Evolve

Once a fraudulent refund is secured, the focus shifts to converting funds into usable, untraceable assets.

Common cash-out methods include:

  • Direct deposits into accounts controlled by the fraudster
  • Accounts opened by “clients” on behalf of the operation
  • Digital banking platforms and payment apps
  • Prepaid cards and alternative financial instruments

Increasingly, threat actors are moving funds into cryptocurrency to reduce traceability. This often involves:

  • Using verified exchange accounts to pass KYC requirements
  • Converting refunds into Bitcoin or other assets
  • Transferring funds to wallets controlled by the fraudster

In some workflows, the entire process — from filing to conversion — can occur within a single mobile or digital ecosystem.

Fraud Communities Enable Scale and Adaptation

Tax refund fraud does not operate in isolation. It is embedded within broader fraud ecosystems where identity data, tools, and tutorials are continuously shared.

Telegram remains a central hub for this activity, with large channels distributing:

  • Screenshots of successful refunds
  • Tutorials and “sauce” (paid or free methods)
  • Listings for identity data and services

Dark web forums also host discussions, though typically with lower volume and higher signal.

The structure of these communities allows fraud techniques to spread quickly, adapt to changing controls, and persist across multiple platforms.

What This Means for Threat Intelligence Teams

Tax refund fraud reflects a broader shift toward operationally mature, community-driven fraud ecosystems.

Flashpoint analysts assess that these schemes are becoming more structured, with clearly defined workflows for identity acquisition, verification bypass, and monetization.

For security and intelligence teams, this has several implications:

  • Identity data remains a critical point of exposure across multiple fraud types
  • Verification systems are actively targeted and tested by threat actors
  • Social engineering continues to bridge technical and human vulnerabilities
  • Fraud techniques are rapidly shared, refined, and scaled across communities

Understanding how these components connect is essential for identifying emerging fraud patterns and anticipating how threat actors will adapt.

Supporting Security Teams with Threat Intelligence During Tax Season and Beyond

Understanding how tax fraud schemes are executed from identity sourcing to verification bypass and cash-out provides critical context for detecting and disrupting fraudulent activity.

Flashpoint delivers leading intelligence that helps organizations monitor fraud communities, track evolving tactics, and identify emerging schemes before they scale. By combining primary source collection with contextual analysis, security teams can move from reactive detection to proactive defense.

To learn how Flashpoint can support your team with real-time intelligence and analysis, request a demo.

Frequently Asked Questions About Tax Refund Fraud

What is tax refund fraud?

Tax refund fraud is a form of identity-based financial crime in which threat actors file fraudulent tax returns using stolen or manipulated personal information to obtain refund payments before the legitimate taxpayer files.

How do threat actors obtain the information needed to commit tax fraud?

Threat actors typically rely on stolen identity data, often referred to as “fullz,” which includes a victim’s name, date of birth, address, and Social Security number. This information is sourced from infostealer malware logs, phishing campaigns, data breaches, social engineering, and illicit marketplaces.

In some cases, fraudsters also recruit “clients” who provide real tax documents or assist in verification processes.

How do fraudsters bypass identity verification for tax returns?

Fraudsters use a combination of tactics to bypass identity and return verification, including:

  • Accessing or creating verified identity accounts used for tax authentication
  • Obtaining prior-year tax data such as adjusted gross income (AGI)
  • Using stolen or socially engineered identity protection (IP) PINs
  • Responding to IRS verification requests using scripts, impersonation, or cooperating individuals

These methods allow fraudulent returns to appear legitimate during processing.

What are common tax fraud tactics used by threat actors?

Common tactics include:

  • Filing returns using stolen personal information
  • Inflating income or tax withholding amounts to increase refunds
  • Claiming fraudulent dependents or tax credits
  • Submitting false wage data to government systems before filing
  • Using real tax forms combined with manipulated data

These approaches are often shared and refined within fraud communities.

What is a “fullz” in tax fraud?

A “fullz” refers to a complete set of personally identifiable information (PII) about an individual, typically including name, date of birth, address, and Social Security number. Fullz are used by fraudsters to file tax returns, open accounts, and conduct other identity-based financial crimes.

How do fraudsters cash out fraudulent tax refunds?

After a fraudulent return is accepted, threat actors typically attempt to convert the refund into usable funds through:

  • Direct deposits into controlled or intermediary accounts
  • Accounts opened by recruited participants
  • Digital banking platforms or prepaid cards
  • Cryptocurrency conversion using verified exchange accounts

The goal is to move funds quickly and reduce traceability.

Why is tax refund fraud difficult to detect?

Tax refund fraud can be difficult to detect because it leverages legitimate systems and processes, including real identity data, authentic tax preparation services, and verified accounts. Fraudsters also adapt quickly by sharing new techniques and bypass methods across online communities.

How do fraud communities support tax refund fraud schemes?

Fraud communities, particularly on platforms like Telegram and dark web forums, enable threat actors to share tutorials, tools, and identity data. These communities accelerate the spread of techniques, allowing fraud schemes to scale and evolve rapidly.

What should security and fraud teams monitor to detect tax fraud activity?

Teams should monitor for:

  • Unusual access to identity data or tax-related accounts
  • Indicators of compromised credentials or identity verification systems
  • Discussions of tax fraud methods, tutorials, or cash-out techniques in illicit communities
  • Patterns in fraudulent filings or refund activity

Incorporating intelligence from fraud communities can provide early visibility into emerging tactics.

How does Flashpoint help organizations detect and prevent tax refund fraud?

Flashpoint helps organizations detect and respond to tax fraud by providing intelligence on how threat actors source identity data, bypass verification systems, and cash out fraudulent returns.

Through primary source collection across platforms like Telegram and dark web forums, Flashpoint enables teams to monitor fraud communities, identify emerging tactics, and understand how schemes are evolving. This intelligence helps organizations move from reactive detection to more proactive identification of fraud risk.

Begin your free trial today.

The post Tax Refund Fraud in 2026: How Threat Actors Exploit Identity, Verification, and Cash-Out Channels appeared first on Flashpoint.

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