In July 2026, Microsoft Defender Experts observed phishing campaigns targeting organizations across multiple industries that distributed a masqueraded MSP360 Remote Monitoring and Management (RMM) installer through meeting invitations, PDF-themed lures, software update prompts, and other social-engineering content. Once executed, the legitimate MSP360 installer, distributed under a deceptive file name established remote management access on affected devices and enabled threat actors to gain an initial foothold using trusted administrative software.

Microsoft observed the MSP360 deployment being used to download and install a ConnectWise ScreenConnect client, creating a secondary remote-access channel that provided redundant access to compromised systems. Microsoft did not observe exploitation of ScreenConnect software itself; rather, threat actors abused legitimately obtained remote administration software to establish and maintain access. After access was established, threat actors used these remote administration channels to deploy additional tools and conduct post-compromise activity, including information collection and credential-access operations.

This activity highlights how threat actors continue to abuse legitimate remote administration software to blend into normal IT operations while maintaining persistent access and reducing detection opportunities. Microsoft Defender for Endpoint detects suspicious and uncommon remote-management activity, while the hunting queries and mitigations in this post can help organizations identify and restrict unapproved RMM use.

Attack chain overview

The observed multi-stage intrusion chain began when phishing lures delivered a legitimate, digitally signed MSP360 RMM v2.5.0.67 installer under deceptive filenames. Following successful User Account Control (UAC) elevation, the installer established MSP360 services for persistent access and leveraged the RMM agent to invoke PowerShell, download, and silently install ConnectWise ScreenConnect.

This effectively introduced a second remote administration channel on the compromised device, which the threat actor subsequently used to transfer and execute additional tooling supporting credential access, local data collection, and other post-compromise activity.

Initial Access: Phishing Campaign Delivering Masqueraded MSP360 RMM Installer

Microsoft observed multiple phishing campaigns that used a multi-stage delivery chain to distribute legitimate, digitally signed MSP360 RMM software (v2.5.0.67). Phishing emails directed users to actor-controlled landing pages that impersonated document-sharing portals, invitation workflows, Adobe Reader download pages, Zoom installation pages, and business collaboration platforms.

Upon user interaction, victims were redirected to download locations hosted on both attacker-controlled infrastructure and legitimate cloud services including Amazon S3, Cloudflare R2, Dropbox, GitLab, and Supabase. The downloaded executables used filenames crafted to resemble legitimate business content, meeting invitations, PDF documents, and software installers. Analysis of downloaded samples showed that many ultimately contained the same MSP360 RMM installer package despite appearing as different files to the victim.

MSP360 SHA256: 108ef7e628d7a20bd6241a5b57149e27a6061f467123eb64061975559f8f73dc

MSP360 SHA1: f34330d4c6e0aa978dc3af40360c14b31ad51127

Observed lure themes:

We have observed the threat actor using multiple social-engineering themes, including:

• Workplace meeting requests
• Zoom and Google Meet installation prompts
• Adobe Acrobat and PDF reader updates
• RSVP invitations and e-cards
• Job offer documents
• Document review and signature requests
• DHL and package-delivery themed content

Examples of observed filenames included:

• VIP_ECARD_INVITATION_rmm_v2.5.0.67_oid[redacted].exe
• ZoomSetup_Installation_v2.5.0.67_ oid[redacted].exe
• PDF Reader & Editor the Adobe Acrobatte_rmm_v2.5.0.67_ oid[redacted].exe
• RSVP_INVITATION_E_CARD_rmm_v2.5.0.67_ oid[redacted].exe
• SSA.GOV_STATEMENT_rmm_v2.5.0.67_ oid[redacted].exe

The campaign relied on a diverse set of payload-hosting mechanisms. Microsoft observed the actor distributing the payload through attacker-controlled domains, websites assessed to be compromised, and legitimate cloud-hosted services. Cloud-hosted services used for payload distribution included Amazon S3, Cloudflare R2, Dropbox, GitLab, and Supabase.

This approach enabled the actor to rapidly rotate delivery infrastructure while continuing to distribute the same MSP360 installer using different lure themes and filenames.

RMM platforms are attractive to threat actors because they are designed to provide administrators with broad remote management capabilities across managed endpoints, including remote command execution, software deployment, file transfer, and persistent service-based access. When abused, these same capabilities can give threat actors a flexible post-compromise channel for maintaining access, deploying additional tooling, and conducting follow-on activity while blending in with legitimate remote administration workflows.

MSP360 RMM installation and foothold establishment

After victims downloaded and executed the masqueraded MSP360 installer, the binary launched from the user’s Downloads directory under a filename designed to resemble a legitimate business document.

The installer subsequently dropped multiple installation components, including System.dll, nsExec.dll, and UAC.dll, to the following folder paths before relaunching itself through an elevation workflow generated by the installer framework. Next, the installer invoked a Windows User Account Control (UAC) elevation workflow. In observed successful installations, the process continued with elevated privileges, allowing deployment of MSP360 components and services. In unsuccessful installations, the elevation did not complete, and deployment terminated before the software was fully installed.

Following elevation, the installer initiated the MSP360 installation workflow and recorded installation status messages using Windows eventcreate.exe. The installer generated “Begin installation” and “End installation. MSP360 de Success.” events under the event source: MSP360 RMM Agent installer. The installer dropped multiple MSP360 plugins and binaries within the installation directory: C:\Program Files\RMM Agent\.

The installer also performed prerequisite discovery by enumerating installed .NET runtimes using: dotnet –list-runtimes. To establish long-term access on the affected device, the installer registered two Windows services: RMM.Agent.exe & RMM.Agent.Launcher.exe. Microsoft observed events indicating stopping any existing MSP360 services and installing new MSP360 services.

In addition to service-based persistence, the installer created registry-based autorun entries for MSP360 user interface components, ensuring the tray applications would automatically launch when users signed in.

The installation routine also modified the Windows Firewall configuration by creating an inbound allow rule for the MSP360 agent. The rule allowed inbound UDP traffic to C:\Program Files\RMM Agent\RMM.Agent.exe on port 48678. This configuration enabled network communications required by the remote management platform.

Not every execution of the installer resulted in a successful deployment. In some instances, the installer was launched by the user and began its installation routine but subsequently attempted to obtain elevated privileges through User Account Control (UAC). When elevation was denied or aborted, the installation terminated before completing deployment of the MSP360 RMM components. The process execution flow showed installation initialization activity followed by events indicating that administrative privileges were required, with no subsequent evidence of the persistence mechanisms, services, or remote management functionality observed during successful installations.

Remote command execution from MSP360 Agent and ScreenConnect deployment

Following successful installation of MSP360 RMM, the newly installed RMM.Agent.exe service launched PowerShell. The PowerShell process modified the execution policy for the current session and executed Invoke-WebRequest commands to download an MSI package named ClientSetup.msi from actor-controlled infrastructure. The downloaded package was then installed silently through msiexec.exe using the /qn switch, eliminating visible user interaction. This installation activity resulted in the deployment of a ConnectWise ScreenConnect client on the compromised endpoint, including ScreenConnect.ClientService.exe, ScreenConnect.WindowsClient.exe, and supporting components.

The installer additionally created Windows service registrations, application uninstall entries, and authentication-related registry modifications associated with the newly deployed ScreenConnect client.

Following deployment, the ScreenConnect client service launched with configuration parameters referencing actor-controlled infrastructure and subsequently established successful outbound communications. The service then spawned ScreenConnect.WindowsClient.exe, providing an additional remote access channel independent of MSP360. Following establishment of the ScreenConnect session, the threat actor used ScreenConnect to transfer and stage additional executables in the following directories:

• C:\Users\%user%\OneDrive\Documents\ScreenConnect\Temp\
• C:\Users\%user%\Documents\ScreenConnect\Temp\

Examples of frequently observed files included:

• WindVerify.exe
• WindowsUpdate.exe
• WindowsSecurity_PIN.exe
• WindowsSecurity_Password.exe
• WindowsPassKey.exe
• SCHider.exe
• PIN.exe
• phonepc.exe
• DefenderDT.exe
• DefenderControl.exe
• phonelinkupdate.exe
• PhoneLinkPrompt.exe
• Passwords.EXE
• OpenCamera.exe
• open_phone_link.exe
• MouseHiderGUI.exe
• HideUL.exe
• HideMouseApp.dll
• HideMouse.exe
• HideFromControlPanel.exe
• HideCursor.exe
• BannerHider.exe
• WebBrowserBookmarksView.exe
• WebBrowserPassView.exe

These files were among the most frequently observed utilities delivered by the threat actor following establishment of a ScreenConnect session. Several filenames were intentionally chosen to resemble legitimate Windows, Microsoft Defender, Phone Link, and security-related components, likely to reduce user suspicion and blend into normal operating system activity. These utilities were observed during post-compromise activity and were used to support subsequent operations on affected systems. Several of the observed tools are commonly associated with credential access, information collection, execution of additional payloads, and efforts to reduce defender visibility.

The execution of these files occurred through ScreenConnect’s built-in RunFile functionality, which allows files to be transferred to and executed on managed endpoints. This activity demonstrates how the threat actor leveraged a legitimate MSP360 RMM deployment to establish an initial foothold before deploying ConnectWise ScreenConnect as a secondary remote access platform. The combination of MSP360 and ScreenConnect provided the threat actor with redundant remote administration channels and enabled the transfer, execution, and management of additional tooling during subsequent stages of the intrusion.

The threat actor subsequently used these remote access platforms to facilitate follow-on activities including information collection, credential access, and the deployment of additional utilities on compromised systems.

Microsoft also observed separate activity during July in which FaronicsDeployAgent.exe, a legitimate deployment and remote access application, was used in a similar manner to MSP360 RMM. In this activity, the threat actor leveraged FaronicsDeployAgent.exe as the initial remote management platform and subsequently used it to download and install ScreenConnect. This observation demonstrates that the deployment of ScreenConnect was not limited to MSP360-based intrusions, with additional legitimate remote administration software also being leveraged to establish remote access and facilitate ScreenConnect installation.

Attribution

Microsoft has not attributed this activity to a named threat actor. The campaigns are tracked as unattributed activity.

Mitigation and protection guidance

Microsoft recommends the following actions to help organizations reduce their exposure to this activity. Check the recommendations card for the deployment status of monitored mitigations.

• Govern approved RMM tools: For approved RMM systems used in your environment, enforce security settings where possible to implement multi-factor authentication (MFA).
• Restrict unauthorized software: Use Application Control for Windows to create policies to block unapproved IT management tools. Both solutions include functionality to block specific software publisher certificates:
  • Application Control for Windows file rule levels allow administrators to specify the level at which they want to trust their applications, including listing certificates as untrusted.
  • AppLocker’s publisher rule condition is available for files that are digitally signed, which can enable organizations to block non-approved RMM instances that include publisher information.
• Block specific signed applications: Microsoft Defender for Endpoint also provides functionality to block specific signed applications using the block certificate action.
• Consider searching for unapproved RMM software installations (see the Advanced hunting section). If an unapproved installation is discovered, reset passwords for accounts used to install the RMM services. If a system-level account was used to install the software, further investigation may be warranted.
• Strengthen endpoint protection: Turn on cloud-delivered protection in Microsoft Defender Antivirus or the equivalent for your antivirus product to cover rapidly evolving attacker tools and techniques. Cloud-based machine learning protections provide near-instant, automated protection against new and emerging threats.
• Investigate unauthorized installations: Turn on the following attack surface reduction rule to block or audit activity associated with this threat:
  • Use advanced protection against ransomware
  • Block process creations originating from PsExec and WMI commands. Some organizations may experience compatibility issues with this rule on certain server systems but should deploy it to other systems to prevent lateral movement originating from PsExec and WMI

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.

Threat intelligence reports

Microsoft customers can use Microsoft Defender XDR Threat Analytics and related Microsoft threat intelligence reporting to stay current on the malicious activity, indicators, detection coverage, and recommended response actions associated with this campaign. These reports provide investigation context, protection guidance, and updated intelligence that security teams can use to prevent, mitigate, or respond to related activity in their environments.

Advanced hunting

// Run this query to identify the presence of MSP360 RMM agent

let MSP360RMM = "108ef7e628d7a20bd6241a5b57149e27a6061f467123eb64061975559f8f73dc";
DeviceFileEvents
| where Timestamp >= ago(30d)
| where SHA256 =~ MSP360RMM

// Run this query to identify the remote command execution from MSP360 RMM Agent

DeviceProcessEvents
| where Timestamp >= ago(30d)  
| where (InitiatingProcessVersionInfoCompanyName == "MSP360" and ProcessCommandLine == "\"powershell.exe\"") or ( InitiatingProcessCommandLine == "\"powershell.exe\"" and ProcessCommandLine has_all ("msiexec.exe","\\Temp\\",".msi") and InitiatingProcessParentFileName == "RMM.Agent.exe")

// Run this query to identify the suspicious network connections from the threat actor’s use of ScreenConnect

let MaliciousURLs =  DeviceNetworkEvents
| where Timestamp >= ago(30d)
| where InitiatingProcessCommandLine == "\"powershell.exe\""
| where InitiatingProcessParentFileName == "RMM.Agent.exe"
| where isnotempty(RemoteUrl)
| distinct  RemoteUrl;
DeviceNetworkEvents
| where Timestamp >= ago(30d)
| where InitiatingProcessFileName has_any ( "ScreenConnect.ClientService.exe","ScreenConnect.WindowsClient.exe","ScreenConnect.Client.exe")
| where isnotempty(RemoteUrl)
| where RemoteUrl in (MaliciousURLs)

// Run this query to identify the suspicious payloads dropped and launched by the threat actor’s use of ScreenConnect

DeviceProcessEvents
| where Timestamp >= ago(30d)  
| where InitiatingProcessCommandLine  has_all ("ScreenConnect.WindowsClient.exe", "RunFile","\\Documents\\","\\Temp\\")

MITRE ATT&CK Techniques observed

This campaign has exhibited use of the following attack techniques. For standard industry documentation about these techniques, refer to the MITRE ATT&CK framework.

Resource Development

• T1583.001 Acquire Infrastructure: Domains | Domains were used to host phishing landing pages, payload delivery infrastructure, and ScreenConnect services associated with the campaign.
• T1583.006 Acquire Infrastructure: Web Services | The threat actor leveraged legitimate cloud-hosting providers including Amazon S3, Cloudflare R2, Dropbox, GitLab, and Supabase for payload distribution.

Initial Access

• T1566.002 Phishing: Spearphishing Link | Victims received workplace meeting, Zoom, Google Meet, invitation, RSVP, PDF, and Adobe-themed phishing emails containing links that redirected to malicious payload download locations.
• T1204 User Execution | Victims downloaded and executed a masqueraded MSP360 installer distributed under deceptive filenames designed to resemble legitimate business documents and software.

Execution

• T1059.001 Command and Scripting Interpreter: PowerShell | The MSP360 RMM.Agent.exe service launched PowerShell to download and install ConnectWise ScreenConnect.
• T1059.003 Command and Scripting Interpreter: Windows Command Shell | Installation workflows used cmd.exe for logging, prerequisite checks, file management, and installation-related tasks.
• T1218.007 System Binary Proxy Execution: Msiexec | The downloaded ClientSetup.msi package was installed silently using msiexec.exe /qn.

Persistence

• T1543.003 Create or Modify System Process: Windows Service | MSP360 and ScreenConnect were installed as Windows services to establish persistent access.
• T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder | MSP360 created registry Run entries to automatically launch tray application components at user logon.

Defense Evasion

• T1036 Masquerading | The actor distributed legitimate MSP360 software under filenames designed to resemble meeting applications, invitations, PDFs, and business documents.
• T1036.005 Match Legitimate Name or Location | Follow-on tooling used filenames that closely resembled legitimate Windows, Microsoft Defender, security, and Phone Link applications.
• T1112 Modify Registry | MSP360 and ScreenConnect modified registry locations associated with services, persistence, credential provider components, protocol handlers, and uninstall entries.

Command and Control

• T1219 Remote Access Software | The threat actor abused legitimate remote administration software including MSP360 RMM and ConnectWise ScreenConnect to maintain access to victim systems.
• T1105 Ingress Tool Transfer | MSP360 downloaded ScreenConnect, while the threat actor’s use of ScreenConnect was subsequently used to transfer and execute additional tooling on compromised endpoints.
• T1071.001 Application Layer Protocol: Web Protocols | PowerShell and ScreenConnect communicated with actor-controlled infrastructure over HTTP/HTTPS.
• T1573 Encrypted Channel | Payload retrieval and remote access communications occurred over encrypted network channels.
• T1102 Web Service | Multiple cloud-hosted web services were used throughout the delivery and command-and-control infrastructure.

Discovery

• T1082 System Information Discovery | The installer enumerated installed .NET runtimes using dotnet –list-runtimes during the installation workflow.

Collection

• T1005 Data from Local System | Additional tooling delivered through ScreenConnect was observed in post-compromise activity and used to collect information from victim devices.

Indicators of compromise (IOCs)

Observed indicators associated with this campaign are listed below.

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.

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

• Learn more about securing Copilot Studio agents with Microsoft Defender 
• Evaluate your AI readiness with our latest Zero Trust for AI workshop.
• Microsoft 365 Copilot AI security documentation
• How Microsoft discovers and mitigates evolving attacks against AI guardrails
• Prompt injection protection in Microsoft Defender for Office 365 – official documentation of the prompt injection protection in Microsoft Defender for Office 365.
• How Microsoft discovers and mitigates evolving attacks against AI guardrails | Microsoft Security Blog
• Manipulating AI memory for profit: The rise of AI Recommendation Poisoning | Microsoft Security Blog – a related example of an AI-era technique observed in email traffic
• Defending the inbox against prompt injection attacks | Microsoft Defender for Office 365 Blog – feature announcement introducing prompt injection protection in Microsoft Defender for Office 365.
• Learn how Microsoft is reimagining the SOC for the agentic era with ISOC in Microsoft Defender

The post Phishing Abuses RMM Tools for Persistent Access appeared first on Microsoft Security Blog.

Since January 2026, Microsoft has observed Russian state threat actor Star Blizzard evolve their detection evasion capabilities through large-scale phishing campaigns, the use of accounts on compromised websites, and a novel malware delivery technique that Microsoft tracks as “RedFlick”. These changes represent a notable shift in the actor’s operational tradecraft and support ongoing cyberespionage activity targeting Ukrainian individuals and institutions as well as international non-government organizations (NGOs), Western think tanks, governments, and other organizations associated with international policy—particularly those with a nexus in supporting Ukraine.

As part of this evolution, Star Blizzard adopted RedFlick, a malware delivery technique that helps evade detection by initiating a set of scheduled tasks to deploy the actor’s custom backdoor, CosmicPulse. This technique is a notable departure from the actor’s previous use of ClickFix-based infection chains which required victims to complete multiple actions before CosmicPulse could be installed. By contrast, the RedFlick infection flow only requires a single user interaction, reducing friction in the compromise process. Combined with the actor’s shift toward large-scale phishing operations during the same period, these changes likely improve Star Blizzard’s ability to reach more targets, evade detection, and increase the likelihood of successful compromise.

This blog provides updated technical analysis of Star Blizzard’s tactics, techniques, and procedures (TTPs) observed throughout 2026, building on our 2025 and 2023 blogs. It details the actor’s evolving phishing, persistence, and malware delivery techniques, and provides recommendations, indicators of compromise (IOCs), detections, and hunting guidance to help organizations identify and defend against RedFlick-related activity. As with any observed nation-state actor activity, Microsoft directly notifies customers that have been targeted or compromised, providing them with recommendations and mitigations to secure their accounts.

Star Blizzard TTPs observed in 2026

Star Blizzard is attributed by the United States Cybersecurity and Infrastructure Agency (CISA) as subordinate to the Russian Federal Security Service Centre (FSB) Centre 18. Star Blizzard periodically overhauls their TTPs to avoid detection, often in response to public exposure of the actor’s campaigns that have involved targeted social engineering through messaging apps and credential theft. Since Google Threat Intelligence Group published its report on Star Blizzard’s COLDCOPY malware in October 2025, Microsoft observed the actor refine their initial access and evasive techniques to include:

• Moving away from targeted spear phishing to large-scale initial contact phishing campaigns
• Using compromised websites to create accounts to send phishing emails
• Updating malware deployment to facilitate the installation of a CosmicPulse downloader

As of the writing of this blog, the RedFlick campaigns have targeted Ukrainian individuals and institutions, as well as international NGOs, think tanks, governments, and financial institutions that have supported Ukraine politically or financially. Microsoft has observed this activity affect over 100 organizations primarily in the United States and United Kingdom, consistent with Star Blizzard’s longstanding targeting priorities.

Microsoft continues to observe some previously reported Star Blizzard phishing techniques throughout 2026; however, the TTPs discussed in this blog have been associated primarily with the actor’s new larger-scale phishing campaigns.

Larger-scale initial contact phishing

Microsoft previously reported on Star Blizzard’s spear-phishing campaigns observed during 2023-2024. During these operations, the actor continued to rely on their conventional TTPs such as initiating email contact with targets before sending a follow-up containing a malicious link, to actor-controlled/compromised infrastructure purposed for credential theft, while impersonating known political or diplomatic figures to lure victims into responding.

In 2026, Microsoft observed Star Blizzard shift from exclusively targeted spear-phishing operations to also conducting larger-scale phishing campaigns. The larger-scale phishing operations were observed at a scale not previously seen from the actor, ranging from tens to hundreds of email messages per campaign. This change likely reflects the actor’s adoption of a mass-mailing phishing platform to automate campaign execution and increase the likelihood of successful compromises by significantly expanding the initial targeting pool. The progression of these campaigns is summarized in the following timeline, including examples of Star Blizzard’s phishing subject lines, targeting details, and the malware delivery methods observed across each campaign:

• January
  • “Повідомлення про результати податкової перевірки” (Notice of tax audit results) – Campaign targeting unidentified Ukraine persons with an attached RedFlick lure.
• February
  • “списання з Вашого рахунку за оплату штрафу” (Debiting from your account for payment of a fine) – Campaign targeting unidentified Ukraine persons with an attached RedFlick lure.
• March
  • “Invitation to an IISS [Private Roundtable/Closed-Door Discussion] on European Security” – Initial contact campaign targeting government officials, security researchers, academia, media, and NGOs. Respondents received a RedFlick lure attachment.
  • “Invitation to a Closed CES Roundtable Discussion” – Initial contact campaign targeting US and Europe technology-sector organizations. Respondents received a RedFlick lure attachment.
  • “Atlantic Council Closed-Door Strategic Discussion” – Initial contact campaign targeting government officials, foreign policy practitioners, security researchers, academia, media, and NGOs. Respondents received a link to DarkSword iOS backdoor installation.
• April
  • “Closed-Door Online Session on Global Capital Allocation & M&A” – Initial contact campaign targeting international financial organizations and researchers. Respondents received a RedFlick lure attachment.
• May
  • “Future of Peace Operations Forum – A Closed Strategic Dialogue” – Initial contact campaign targeting diplomatic and multilateral organizations. Respondents received a RedFlick lure attachment.
  • “Future of Liberty Forum” – Initial contact campaign targeting employees of a US-based think tank. Respondents received a RedFlick lure attachment.
• June
  • “Invitation to the MAMA Summit on the Current Situation Surrounding the Ukrainian Crisis” – Initial contact campaign targeting incumbent/former diplomatic staff. Respondents received a RedFlick lure attachment.
  • “Invitation to the Chatham House London Conference 2026 – 9 July 2026” – Initial contact campaign targeting think tanks, NGOs, and national parliamentary. Respondents received a RedFlick lure attachment.
• July
  • “Thought you might find this USUBC roundtable of interest” – Initial contact campaign targeting think tanks, NGOs, and Ukraine civil society. Respondents received a RedFlick lure attachment.
  • “Інформація щодо тимчасового відключення водопостачання” (Information about temporary water supply shutdown) – Targeted Kyiv-based hotels with an attached RedFlick lure.
• August
  • “Payment Advice Note from 06.08.2026” – Targeted employees of an international financial organization with an attached RedFlick lure.

Once a recipient responds to the initial phishing email, Star Blizzard typically sends a follow-up message containing a password-protected RAR or ZIP archive. The archive contains files that initiate the RedFlick infection flow. The password is included as an image in the follow-up email shown in Figure 1, along with additional examples of Star Blizzard follow-up emails below:

Since January 2026, Microsoft observed at least 13 distinct large-scale phishing campaigns targeting primarily NGOs, think tanks, and government organizations worldwide. The earliest campaigns, observed between January and February, targeted unspecified users of the Ukraine email provider Ukr.net. These emails impersonated Ukrainian authorities and were themed as notifications of a tax audit or outstanding fine.

Beginning in March 2026, Star Blizzard expanded targeting outside of Ukraine. Subsequent campaigns frequently used lures themed as invitations to conferences or events purportedly organized by a reputable think tank or NGO. Microsoft also observed the actor target multiple individuals within the same organization, with phishing emails often crafted to appear as internal communications originating from the targeted organization itself. The actor’s shift from Ukraine-focused operations to global targets could indicate Star Blizzard initially targeted Ukraine to test their new capabilities.

The large-scale campaigns have demonstrated capabilities previously unassociated with Star Blizzard. For example, a campaign observed in mid-August 2026 employed steganography to conceal identifiers. Throughout 2026, Star Blizzard has also continued to develop additional operational capabilities. Notably, ProofPoint reported in March that the actor had targeted vulnerable Apple iOS devices to deploy the DarkSword backdoor.

Creating accounts on compromised websites

Since March 2026, Star Blizzard has made another notable change to their TTPs to support the higher-volume phishing operations, using accounts created on compromised websites to send phishing emails to targets. This change coincided with the actor’s shift to larger-scale phishing campaigns and has been observed almost exclusively in support of these operations. Previously, the actor would create accounts on free email services (predominantly using Protonmail and Microsoft consumer accounts) to impersonate an individual that would be well known to the prospective target, whether it was a political figure, academic, or former diplomat. In the large-scale campaigns, Star Blizzard has used accounts created on websites hosted on CPanel and WordPress, using the same account name across multiple website domains. Microsoft Threat Intelligence assesses with high confidence that these websites have been compromised by Star Blizzard for this purpose.

Updating malware delivery and installation TTPs

Between January and August 2026, Microsoft observed multiple waves of Star Blizzard phishing campaigns alongside notable changes in the actor’s initial access TTPs, particularly the use of RedFlick scheduled tasks. During this period, Microsoft observed three significant shifts in the threat actor’s delivery techniques.

From ClickFix to VHDX

In mid-January 2026, Microsoft observed the use of a malicious Virtual Hard Disk v2 (VHDX), delivered through a phishing email containing a password-protected ZIP file. The VHDX file ships a malicious LNK file disguised as a PDF document, alongside a hidden directory containing a BAT script and a legitimate decoy PDF.

When the victim opens the LNK file, conhost.exe is launched in a hidden window and cmd.exe is subsequently spawned to execute the embedded BAT script:

The BAT file opens the decoy PDF and invokes SSH.exe with PermitLocalCommand enabled, ultimately downloading and executing a remotely hosted MSI installer:

In multiple campaigns, Microsoft observed an MSI installer creating a scheduled task that uses control.exe to download and execute a remotely hosted CosmicPulse downloader masquerading as a Control Panel applet (CPL). Unlike earlier campaigns that relied on ClickFix lures and user interaction, this approach relies on compiling the CosmicPulse downloader as a Control Panel applet DLL.

The shift from interactive user execution to remote execution and masquerading as a CPL item highlights an evolution in both persistence and defense evasion techniques.

CosmicPulse downloader

The Control Panel applet DLL is a downloader with the sole purpose of downloading and installing a version of CosmicPulse, a malicious Python backdoor, on the target device. The downloader is also known publically as NOROBOT or BAITSWITCH.

Similar to previous versions, this downloader downloads, persists, and executes a version of CosmicPulse on the infected device. Upon execution, it downloads two ZIP files and stores them on disk. It then writes an encrypted AES key to the HKEY_CURRENT_USER\Software\Classes\.mollis registry key. One ZIP file contains a Python 3.8 64-bit package and a Python file that serves as the CosmicPulse bootstrapper. The bootstrapper reads the encrypted key from the registry, recovers it using an embedded key in AES-ECB mode, and then uses the recovered key to decode the CosmicPulse payload (also known as YESROBOT) contained in the second ZIP file. The below image shows the process of the CosmicPulse installation.

Since January 2026, Microsoft has observed the CosmicPulse backdoor going through various little changes to circumvent existing signatures. However, the capabilities and purpose of this backdoor remain the same as described in previous articles.

Persistence through multiple scheduled tasks

In April 2026, Microsoft observed Star Blizzard changing persistence tactics to include RedFlick scheduled tasks. Whereas a malicious MSI file installed a single scheduled task in January—by April, the actor’s MSI installer created three scheduled tasks masquerading as legitimate network components, each with their own purpose. The TTPs have overlaps with the spear-phishing campaigns reported by the Digital Security Lab Ukraine (DLUA) in June 2026. In at least one incident, Microsoft has observed either the first or third task deploying an instance of CosmicPulse on the infected machine.

Task 1 – Registration beaconing and dynamic DLL execution task

The first task masquerades as a legitimate Internet Quality Test Connection task. The scheduled command serves two purposes. First, it sends a UTF-16 and Base64-encoded string containing the network or computer name and the username of the infected device to the C2 server. Thereby, it exfiltrates basic information about the infected host.

Second, an attacker-controlled DLL can be executed remotely through invoking Control_RunDLL from Shell32.dll. Microsoft was unable to obtain a variant of this payload. The task uses a WebDAV UNC path to access the remote payload, allowing the resource to be retrieved over HTTP rather than through a conventional SMB network share.

Task 2 – Supporting task

The second installed task, named Network Configuration Manager, supports the WebDAV-based execution used by the other tasks. The invoked command causes Windows to treat the UNC-style path as a WebDAV resource and process it through the WebDAV redirector and associated WebClient functionality.

Through WebDAV, Windows applications can interact with a remote web resource as though it is a file or folder path while the underlying communication is performed using HTTP/HTTPS rather than conventional SMB. The task therefore prepares the WebDAV client functionality required by the other scheduled tasks.

Task 3 – CosmicPulse downloader execution

The third installed task, named System Health Monitor, uses control.exe to access a remote path hosted on the hardcoded C2 server and execute the next stage.

Hiding payloads in PDF files

In July 2026, Microsoft observed another change in Star Blizzard’s delivery techniques, this time involving a multistage execution chain.

The phishing email contains a password-protected RAR archive nested inside a ZIP file. After the archive is opened, it exposes an LNK file.

When executed, the LNK file uses conhost.exe and curl to download a PDF from an actor-controlled server:

After downloading the PDF, the command runs a second PowerShell payload. This payload searches the PDF for the magic header cAB, extracts the subsequent 208 bytes of Base64-encoded data, and executes the decoded command through PowerShell. The resulting conhost command, shown below, attempts to download and install another MSI file:

As in previous campaigns, the Python installer contains obfuscated PowerShell code. When executed, the code attempts to create two additional scheduled tasks. The first scheduled task again serves as a helper task, consistent with the supporting tasks observed in previous campaigns. The second scheduled task attempts to download and execute a CPL applet again.

Star Blizzard’s shift from ClickFix-based delivery chains to VHDX files, expanded use of scheduled tasks for persistence, and concealment of payloads within PDF files demonstrate the actor’s continued ability to adapt their delivery methods in response to evolving defenses. The actor’s recent use of PDFs to conceal payloads further illustrates efforts to bypass layered defenses through increasingly complex execution chains. Taken together, these changes demonstrate Star Blizzard’s continued efforts to streamline malware deployment, reduce required user interaction, and improve operational scalability while maintaining its longstanding espionage objectives.

Defending against Star Blizzard and RedFlick-related activity

Microsoft Threat Intelligence advises organizations that are most likely at risk—primarily those in government, NGOs, or think tanks adjacent to Ukraine policy or support—to implement the following recommendations to mitigate against Star Blizzard activity.

Protecting against Star Blizzard phishing

As previously reported, Star Blizzard’s success relies on sophisticated, targeted phishing lures that trick users into engaging with the actor by impersonating trusted contacts. While Star Blizzard has changed their overall TTPs, the actor continues to employ the same phishing patterns against users:

• Star Blizzard continues to impersonate trusted contacts that users or organizations would expect an email from. Star Blizzard also continues using email from free providers such as Proton @proton[.]me, particularly in Evilginx spear-phishing operations observed throughout 2026. However, despite the actor’s recent shift toward leveraging compromised legitimate websites that impersonate real individuals associated with a target’s organization, users can still remain vigilant for other Star Blizzard TTPs, several of which have been observed in previous campaigns:
  • Star Blizzard continues to make initial contact with a target by sending an email, usually without an attachment.
  • If a user engages, Star Blizzard will follow up with an email with an attachment. In this particular campaign, it has been an archive file such as a RAR or ZIP.
  • The email sender contains names of actual persons and organizations they belong to—however, the organization is not within the root or registered domain itself but in the username or local part of the email address. This should draw a red flag to the email’s authenticity. When in doubt, directly contact the person you think sent the email using a previously established and trusted contact method such as known email address or phone number.
  • The emails in these RedFlick campaigns are often sent in bulk.
• To best mitigate against this activity, Microsoft suggests the following policies to strengthen network environments against Star Blizzard phishing operations:
  • Using phishing resistant authentication methods.
  • Lockdown account access using Conditional Access policies.
  • Use advanced anti-phishing solutions like Microsoft Defender for Office 365 that monitor and scan incoming emails and visited websites.
  • Turn on Safe Links and Safe Attachments for Office 365.

Microsoft also recommends the following mitigations to reduce the impact of this threat

• Run endpoint detection and response (EDR) in block mode so that Microsoft Defender for Endpoint can block malicious artifacts, even when your non-Microsoft antivirus does not detect the threat, or when Microsoft Defender Antivirus is running in passive mode. EDR in block mode works behind the scenes to remediate malicious artifacts that are detected post-compromise.
• 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.
• Configure investigation and remediation in full automated mode to allow Microsoft Defender for Endpoint to take immediate action on alerts to resolve breaches, significantly reducing alert volume.
• Turn on cloud-delivered protection and automatic sample submission in Microsoft Defender Antivirus to cover rapidly evolving attacker tools, techniques, and behaviors. These capabilities use artificial intelligence and machine learning to quickly identify and stop new and unknown threats.
• Use security defaults as a baseline set of policies to improve identity security posture. For more granular control, enable Conditional Access policies. Conditional Access policies evaluate sign-in requests using additional identity driven signals like user or group membership, IP location information, and device status, among others, and are enforced for suspicious sign-ins. Organizations can protect themselves from attacks that leverage stolen credentials by enabling policies such as compliant devices or trusted IP address requirements.
• Implement continuous access evaluation.
• Turn on Microsoft Defender Antivirus real-time protection.
• Continuously monitor suspicious or anomalous activities. Investigate sign-in attempts with suspicious characteristics (for example, location, ISP, user agent, and use of anonymizer services).
• Turn on 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.
• Enable network protection to prevent applications or users from accessing malicious domains and other malicious content on the internet.
• Configure Microsoft Defender for Office 365 to recheck links on click. Safe Links provides URL scanning and rewriting of inbound email messages in mail flow, and time-of-click verification of URLs and links in email messages, other Office 365 applications such as Teams, and other locations such as SharePoint Online. Safe Links scanning occurs in addition to the regular anti-spam and anti-malware protection in inbound email messages in Exchange Online Protection (EOP). Safe Links scanning can help protect your organization from malicious links that are used in phishing and other attacks.
• Use the Attack Simulator in Microsoft Defender for Office 365 to organize realistic, yet safe, simulated phishing and password attack campaigns in your organization by training end users against clicking URLs in unsolicited messages and disclosing their credentials. Training should include checking for poor spelling and grammar in phishing emails or the application’s consent screen as well as spoofed app names, logos, and domain URLs appearing to originate from legitimate applications or companies. Note that Attack Simulator testing only supports phishing emails containing links at this time.
• Microsoft Defender customers can turn on attack surface reduction rules to prevent common attack techniques:
  • Block executable files from running unless they meet a prevalence, age, or trusted list criterion
  • Block execution of potentially obfuscated scripts
• Utilize Windows Firewall, Windows Firewall with Advanced Security, or an enterprise firewall/filtering solution to help prevent or restrict outbound SSH connection attempts to external or public networks that are not essential for business.

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 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:

• Threat Intelligence Briefing agent
• Phishing Triage agent
• Threat Hunting agent
• Dynamic Threat Detection agent

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.

• Actor profile: Star Blizzard
• Tool profile: CosmicPulse
• Activity profile: New Star Blizzard spearphishing campaign targets WhatsApp accounts
• Threat overview: Evolving phishing threats

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:

Conhost.exe invokes curl

The following query will detect the use of conhost.exe to launch curl to download a decoy PDF from an actor-controlled server, which Star Blizzard used in July 2026. (Note that this query may detect activity not related to Star Blizzard or necessarily malicious. Please investigate findings to determine if the activity is legitimate.)

DeviceProcessEvents
| where Timestamp > ago(7d)
| where FileName == "conhost.exe"
| where ProcessCommandLine has "curl"
| project Timestamp, DeviceName, AccountName, ProcessCommandLine, InitiatingProcessCommandLine, InitiatingProcessFileName, DeviceId, ProcessId, ProcessUniqueId, InitiatingProcessUniqueId

Invoke SSH to launch local command line

The following query will detect the invocation of SSH to initiate a local command prompt, which Star Blizzard used in January 2026 to download and execute a remotely hosted MSI installer. (Note that this query may detect activity not related to Star Blizzard or necessarily malicious. Please investigate findings to determine if the activity is legitimate.)

DeviceProcessEvents
| where Timestamp > ago(7d)
| where ProcessCommandLine has "ssh.exe"
| where ProcessCommandLine has "PermitLocalCommand=yes"
| where ProcessCommandLine has "LocalCommand=cmd.exe"
| project Timestamp, DeviceName, AccountName, ProcessCommandLine, InitiatingProcessCommandLine, InitiatingProcessParentFileName, DeviceId, ProcessId, InitiatingProcessId, ReportId

Persistence through scheduled tasks

The following query will detect Star Blizzard’s uniquely named scheduled tasks that attempt to masquerade as legitimately-named tasks, used for persistence by Star Blizzard in April 2026.

union isfuzzy=true
(
DeviceProcessEvents
| where Timestamp > ago(7d)
| where ProcessCommandLine has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor") or AdditionalFields has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor")
| project Timestamp, DeviceName, ActionType, ProcessCommandLine, AdditionalFields
, RegistryKey = tostring(dynamic(null)), RegistryValueName = tostring(dynamic(null))
, SourceTable = "DeviceProcessEvents"
, ProcessId, AccountName, AccountDomain, AccountSid
)
,
(
DeviceEvents
| where Timestamp > ago(7d)
| where ProcessCommandLine has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor") or AdditionalFields has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor") or RegistryKey has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor") or RegistryValueName has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor")
| project Timestamp, DeviceName, ActionType, ProcessCommandLine, AdditionalFields, RegistryKey, RegistryValueName
, SourceTable = "DeviceEvents"
, ProcessId = long(null), AccountName = "", AccountDomain = "", AccountSid = ""
)
,
(
DeviceRegistryEvents
| where Timestamp > ago(7d)
| where RegistryKey has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor") or RegistryValueName has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor") or RegistryValueData has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor") or InitiatingProcessCommandLine has_any ("Internet Quality Test Connection","Network Configuration Manager","System Health Monitor")
| project Timestamp, DeviceName, ActionType
, ProcessCommandLine = InitiatingProcessCommandLine, AdditionalFields = ""
, RegistryKey, RegistryValueName
, SourceTable = "DeviceRegistryEvents"
, ProcessId = long(null), AccountName = "", AccountDomain = "", AccountSid = ""
)

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.

let lookback = 30d;
let ioc_ip_addr = dynamic(["103.245.231.248", "2.57.241.246", "89.125.209.168", "103.245.231.79", "45.84.59.66", "103.160.59.97"]);
let ioc_domains = dynamic(["etia.ca", "groy.cc", "gliderrompercycl.com", "muvb.net", "divekickspolic.org", "matjk.click", "bpdaersa.click", "stuseamandesilt.org", "Itechx.tel", "guach.net", "ruten.observer", "byveo.org", "secure-dns-hub.com", "qumel.link", "cyrna.top", "drasw.club"]);
_Im_NetworkSession(starttime=todatetime(ago(lookback)), endtime=now())
| where DstIpAddr in (ioc_ip_addr) or DstDomain has_any (ioc_domains)
| summarize FirstSeen=min(TimeGenerated), LastSeen=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.

let lookback = 30d;
let ioc_ip_addr = dynamic(["103.245.231.248", "2.57.241.246", "89.125.209.168", "103.245.231.79", "45.84.59.66", "103.160.59.97"]);
let ioc_domains = dynamic(["etia.ca", "groy.cc", "gliderrompercycl.com", "muvb.net", "divekickspolic.org", "matjk.click", "bpdaersa.click", "stuseamandesilt.org", "Itechx.tel", "guach.net", "ruten.observer", "byveo.org", "secure-dns-hub.com", "qumel.link", "cyrna.top", "drasw.club"]);
_Im_WebSession(starttime=todatetime(ago(lookback)), endtime=now())
| where DstIpAddr in (ioc_ip_addr)
    or DstDomain has_any (ioc_domains)
    or Url has_any (ioc_domains)
| summarize FirstSeen=min(TimeGenerated), LastSeen=max(TimeGenerated), EventCount=count()
    by SrcIpAddr, DstIpAddr, DstDomain, Url, Dvc, EventProduct, EventVendor

Indicators of compromise

References

• https://www.cisa.gov/news-events/cybersecurity-advisories/aa23-341a
• https://www.zscaler.com/blogs/security-research/coldriver-updates-arsenal-baitswitch-and-simplefix
• https://dslua.org/publications/spearphishing-via-fake-urc-2026-invitations-targets-ukrainian-csos/
• https://cloud.google.com/blog/topics/threat-intelligence/new-malware-russia-coldriver
• https://x.com/threatinsight/status/2037560142880006266

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 Star Blizzard refines phishing and malware delivery with the RedFlick technique appeared first on Microsoft Security Blog.