Introduction

Mandiant is tracking a significant expansion and escalation in the operations of threat clusters associated with ShinyHunters-branded extortion. As detailed in our companion report, 'Vishing for Access: Tracking the Expansion of ShinyHunters-Branded SaaS Data Theft', these campaigns leverage evolved voice phishing (vishing) and victim-branded credential harvesting to successfully compromise single sign-on (SSO) credentials and enroll unauthorized devices into victim multi-factor authentication (MFA) solutions.

This activity is not the result of a security vulnerability in vendors' products or infrastructure. Instead, these intrusions rely on the effectiveness of social engineering to bypass identity controls and pivot into cloud-based software-as-a-service (SaaS) environments.

This post provides actionable hardening, logging, and detection recommendations to help organizations protect against these threats. Organizations responding to an active incident should focus on rapid containment steps, such as severing access to infrastructure environments, SaaS platforms, and the specific identity stores typically used for lateral movement and persistence. Long-term defense requires a transition toward phishing-resistant MFA, such as FIDO2 security keys or passkeys, which are more resistant to social engineering than push-based or SMS authentication.

Containment

Organizations responding to an active or suspected intrusion by these threat clusters should prioritize rapid containment to sever the attacker’s access to prevent further data exfiltration. Because these campaigns rely on valid credentials rather than malware, containment must prioritize the revocation of session tokens and the restriction of identity and access management operations.

Immediate Containment Actions

• Revoke active sessions: Identify and disable known compromised accounts and revoke all active session tokens and OAuth authorizations across IdP and SaaS platforms.

• Restrict password resets: Temporarily disable or heavily restrict public-facing self-service password reset portals to prevent further credential manipulation.  Do not allow the use of self-service password reset for administrative accounts.

• Pause MFA registration: Temporarily disable the ability for users to register, enroll, or join new devices to the identity provider (IdP).

• Limit remote access: Restrict or temporarily disable remote access ingress points, such as VPNs, or Virtual Desktops Infrastructure (VDI), especially from untrusted or non-compliant devices.

• Enforce device compliance: Restrict access to IdPs and SaaS applications so that authentication can only originate from organization-managed, compliant devices and known trusted egress locations.

• Implement 'shields up' procedures: Inform the service desk of heightened risk and shift to manual, high-assurance verification protocols for all account-related requests. In addition, remind technology operations staff not to accept any work direction via SMS messages from colleagues.

During periods of heightened threat activity, Mandiant recommends that organizations temporarily route all password and MFA resets through a rigorous manual identity verification protocol, such as the live video verification described in the Hardening section of this post. When appropriate, organizations should also communicate with end-users, HR partners, and other business units to stay on high-alert during the initial containment phase. Always report suspicious activity to internal IT and Security for further investigation.

1. Hardening 

Defending against threat clusters associated with ShinyHunters-branded extortion begins with tightening manual, high-risk processes that attackers frequently exploit, particularly password resets, device enrollments, and MFA changes.

Help Desk Verification

Because these campaigns often target human-driven workflows through social engineering, vishing, and phishing, organizations should implement stronger, layered identity verification processes for support interactions, especially for requests involving account changes such as password resets or MFA modifications. Threat actors have also been known to impersonate third-party vendors to voice phish (vish) help desks and persuade staff to approve or install malicious SaaS application registrations.

As a temporary measure during heightened risk, organizations should require verification that includes the caller’s identity, a valid ID, and a visual confirmation that the caller and ID match. 

To implement this, organizations should require help desk personnel to:

• Require a live video call where the user holds a physical government ID next to their face. The agent must visually verify the match.

• Confirm the name on the ID matches the employee’s corporate record.

• Require out-of-band approval from the user's known manager before processing the reset.

• Reject requests based solely on employee ID, SSN, or manager name. ShinyHunters possess this data from previous breaches and may use it to verify their identity.

• If the user calls the helpdesk for a password reset, never perform the reset without calling the user back at a known good phone number to prevent spoofing.

• If a live video call is not possible, require an alternative high-assurance path. It may be required for the user to come in person to verify their identity.

• Optionally, after a completed interaction, the help desk agent can send an email to the user’s manager indicating that the change is complete with a picture from the video call of the user who requested the change on camera.

Special Handling for Third-Party Vendor Requests

Mandiant has observed incidents where attackers impersonate support personnel from third-party vendors to gain access. In these situations, the standard verification principals may not be applicable.

Under no circumstances should the Help Desk move forward with allowing access. The agent must halt the request and follow this procedure:

• End the inbound call without providing any access or information

• Independently contact the company's designated account manager for that vendor using trusted, on-file contact information

• Require explicit verification from the account manager before proceeding with any request

End User Education

Organizations should educate end users on best practices especially when being reached out directly without prior notice.

• Conduct internal Vishing and Phishing exercises to validate end user adoption of security best practices.

• Educate that passwords should not be shared, regardless of who is asking for it.

• Encourage users to exercise extreme caution when being requested to reset their own passwords and MFA; especially during off-business hours.

• If they are unsure of the person or number they are being contacted by, have them cease all communications and contact a known support channel for guidance.

Identity & Access Management

Organizations should implement a layered series of controls to protect all types of identities. Access to cloud identity providers (IdPs), cloud consoles, SaaS applications, document and code repositories should be restricted since these platforms often become the control plane for privilege escalation, data access, and long-term persistence.

This can be achieved by:

• Limiting access to trusted egress points and physical locations
• Review and understand what “local accounts” exist within SaaS platforms:
  • Ensure any default username/passwords have been updated according to the organization’s password policy.
  • Limit the use of ‘local accounts’ that are not managed as part of the organization’s primary centralized IdP.
• Reducing the scope of non-human accounts (access keys, tokens, and non-human accounts)
  • Where applicable, organizations should implement network restrictions across non-human accounts. 
  • Activity correlating to long-lived tokens (OAuth / API) associated with authorized / trusted applications should be monitored to detect abnormal activity.
• Limit access to organization resources from managed and compliant devices only. Across managed devices:
  • Implement device posture checks via the Identity Provider.
  • Block access from devices with prolonged inactivity.
  • Block end users ability to enroll personal devices. 
• Where access from unmanaged devices is required, organizations should: 
  • Limit non-managed devices to web only views.
  • Disable ability to download/store corporate/business data locally on unmanaged personal devices.
  • Limit session durations and prompt for re-authentication with MFA.
• Rapid enhancement to MFA methods, such as:
  • Removal of SMS, phone call, push notification, and/or email as authentication controls.
  • Requiring strong, phishing resistant MFA methods such as:
    • Authenticator apps that require phishing resistant MFA (FIDO2 Passkey Support may be added to existing methods such as Microsoft Authenticator.)
    • FIDO2 security keys for authenticating identities that are assigned privileged roles.
  • Enforce multi-context criteria to enrich the authentication transaction.
    • Examples include not only validating the identity, but also specific device and location attributes as part of the authentication transaction.
      • For organizations that leverage Google Workspace, these concepts can be enforced by using context-aware access policies.
      • For organizations that leverage Microsoft Entra ID, these concepts can be enforced by using a Conditional Access Policy.
      • For organizations that leverage Okta, these concepts can be enforced by using Okta policies and rules.

Attackers are consistently targeting non-human identities due to the limited number of detections around them, lack of baseline of normal vs abnormal activity, and common assignment of privileged roles attached to these identities. Organizations should: 

• Identify and track all programmatic identities and their usage across the environment, including where they are created, which systems they access, and who owns them.

• Centralize storage in a secrets manager (cloud-native or third-party) and prevent credentials from being embedded in source code, config files, or CI/CD pipelines.

• Restrict authentication IPs for programmatic credentials so they can only be used from trusted third-party or internal IP ranges wherever technically feasible.

• Transition to workload identity federation: Where feasible, replace long-lived static credentials (such as AWS access keys or service account keys) with workload identity federation mechanisms (often based on OIDC). This allows applications to authenticate using short-lived, ephemeral tokens issued by the cloud provider, dramatically reducing the risk of credential theft from code repositories and file systems.

• Enforce strict scoping and resource binding by tying credentials to specific API endpoints, services, or resources. For example, an API key should not simply have “read” access to storage, but be limited to a particular bucket or even a specific prefix, minimizing blast radius if it is compromised.

• Baseline expected behavior for each credential type (typical access paths, destinations, frequency, and volume) and integrate this into monitoring and alerting so anomalies can be quickly detected and investigated.

Additional platform-specific hardening measures include: 

• Okta

• Enable Okta ThreatInsight to automatically block IP addresses identified as malicious.

• Restrict Super Admin access to specific network zones (corporate VPN).

• Microsoft Entra ID

• Implement common Conditional Access Policies to block unauthorized authentication attempts and restrict high-risk sign-ins.

• Configure risk-based policies to trigger password changes or MFA when risk is detected.

• Restrict who is allowed to register applications in Entra ID and require administrator approval for all application registrations.

• Google Workspace

• Use Context-Aware Access levels to restrict Google Drive and Admin Console access based on device attributes and IP address.

• Enforce 2-Step Verification (2SV) for all Google Workspace users.

• Use Advanced Protection to protect high-risk users from targeted phishing, malware, and account hijacking.

Infrastructure and Application Platforms 

Infrastructure and application platforms such as Cloud consoles and SaaS applications are frequent targets for credential harvesting and data exfiltration. Protecting these systems typically requires implementing the previously outlined identity controls, along with platform-specific security guardrails, including:

• Restrict management-plane access so it’s only reachable from the organization’s network and approved VPN ranges.

• Scan for and remediate exposed secrets, including sensitive credentials stored across these platforms.

• Enforce device access controls so access is limited to managed, compliant devices.

• Monitor configuration changes to identify and investigate newly created resources, exposed services, or other unauthorized modifications.

• Implement logging and detections to identify:

• Newly created or modified network security group (NSG) rules, firewall rules, or publicly exposed resources that enable remote access.

• Creation of programmatic keys and credentials (e.g., access keys).

• Disable API/CLI access for non-essential users by restricting programmatic access to those who explicitly require it for management-plane operations.

Platform Specifics

• GCP

• Configure security perimeters with VPC Service Controls (VPC-SC) to prevent data from being copied to unauthorized Google Cloud resources even if they have valid credentials.
  
  Set additional guardrails with organizational policies and deny policies applied at the organization level. This stops developers from introducing misconfigurations that could be exploited by attackers. For example, enforcing organizational policies like “iam.disableServiceAccountKeyCreation” will prevent generating new unmanaged service account keys that can be easily exfiltrated.

• Apply IAM Conditions to sensitive role bindings. Restrict roles so they only activate if the resource name starts with a specific prefix or if the request comes during specific working hours. This limits the blast radius of a compromised credential.

• AWS

  • Apply Service Control Policies (SCPs) at the root level of the AWS Organization that limit the attack surface of AWS services. For example, deny access in unused regions, block creation of IAM access keys, and prevent deletion of backups, snapshots, and critical resources.

  • Define data perimeters through Resource Control Policies (RCPs) that restrict access to sensitive resources (like S3 buckets) to only trusted principals within your organization, preventing external entities from accessing data even with valid keys.

  • Implement alerts on common reconnaissance commands such as GetCallerIdentity API calls originating from non-corporate IP addresses. This is often the first reconnaissance command an attacker runs to verify their stolen keys.

• Azure
  • Enforce Conditional Access Policies (CAPs) that block access to administrative applications unless the device is "Microsoft Entra hybrid joined" and "Compliant." This prevents attackers from accessing resources using their own tools or devices.
  • Eliminate standing admin access and require Just-In-Time (JIT) through Privileged Identity Management (PIM) for elevation for roles such as Global Administrator, mandating an approval workflow and justification for each activation.
  • Enforce the use of Managed Identities for Azure resources accessing other services. This removes the need for developers to handle or rotate credentials for service principals, eliminating the static key attack vector.
• Source Code Management
  • Enforce Single Sign-On (SSO) with SCIM for automated lifecycle management and mandate FIDO2/WebAuthn to neutralize phishing. Additionally, replace broad access tokens with short-lived, Fine-Grained Personal Access Tokens (PATs) to enforce least privilege.
  • Prevent credential leakage by enabling native "Push Protection" features or implementing blocking CI/CD workflows (such as TruffleHog) that automatically reject commits containing high-entropy strings before they are merged.
  • Mitigate the risk of malicious code injection by requiring cryptographic commit signing (GPG/S/MIME) and mandating a minimum of two approvals for all Pull Requests targeting protected branches.
  • Conduct scheduled historical scans to identify and purge latent secrets that evaded preventative controls, ensuring any compromised credentials are immediately rotated and forensically investigated.
• Salesforce
  • Reference Mandiant’s Salesforce Hardening blog post
  • Reference Salesforce “Protecting Salesforce Data After an Identity Compromise” blog post

2. Logging

Modern SaaS intrusions rarely rely on payloads or technical exploits. Instead, Mandiant consistently observes attackers leveraging valid access (frequently gained via vishing or MFA bypass) to abuse native SaaS capabilities such as bulk exports, connected apps, and administrative configuration changes.

Without clear visibility into these environments, detection becomes nearly impossible. If an organization cannot track which identity authenticated, what permissions were authorized, and what data was exported, they often remain unaware of a campaign until an extortion note appears.

This section focuses on ensuring your organization has the necessary visibility into identity actions, authorizations, and SaaS export behaviors required to detect and disrupt these incidents before they escalate.

Identity Provider 

If an adversary gains access through vishing and MFA manipulation, the first reliable signals will appear in the SSO control plane, not inside a workstation. In this example, the goal is to ensure Okta and Entra ID ogs identify who authenticated, what MFA changes occurred, and where access originated from.

What to Enable and Ingest into the SIEM

Okta

• Authentication events (successful and failed sign-ins)

• MFA lifecycle events (enrollment/activation and changes to authentication factors or devices)

• Administrative identity events that capture security-relevant actions (e.g., changes that affect authentication posture)

Entra ID

• Authentication events

• Audit logs for MFA changes / authentication method

• Audit logs for security posture changes that affect authentication

• Conditional Access policy changes

• Changes to Named Locations / trusted locations

What “Good” Looks Like Operationally

You should be able to quickly identify:

• Authentication factor, device enrollment activity, and the user responsible

• Source IP, geolocation, (and ASN if available) associated with that enrollment

• Whether access originated from the organization’s expected egress and identify access paths

Platform

Google Workspace Logging 

Defenders should ensure they have visibility into OAuth authorizations, mailbox deletion activity (including deletion of security notification emails), and Google Takeout exports. 

What You Need in Place Before Logging

• Correct edition + investigation surfaces available: Confirm your Workspace edition supports the Audit and investigation tool and the Security Investigation tool (if you plan to use it).

• Correct admin privileges: Ensure the account has Audit & Investigation privilege (to access OAuth/Gmail/Takeout log events) and Security Center privilege.

• If you need Gmail message content: Validate edition + privileges allow viewing message content during investigations.

What to Enable and Ingest into the SIEM

OAuth / App authorization logs

Enable and ingest token/app authorization logs to observe:

• Which application was authorized (app name + identifier)

• Which user granted access

• What scopes were granted

• Source IP and geolocation for the authorization

This is the telemetry required to detect suspicious app authorizations and add-on enablement that can support mailbox manipulation.

Gmail audit logs

Enable and ingest Gmail audit events that capture:

• Message deletion actions (including permanent delete where available)

• Message direction indicators (especially useful for outbound cleanup behavior)

• Message metadata (e.g., subject) to support detection of targeted deletions of security notification emails

Google Takeout audit logs

Enable and ingest Takeout logs to capture:

• Export initiation and completion events

• User and source IP/geo for the export activity

Salesforce Logging 

Activity observed by Mandiant includes the use of Salesforce Data Loader and large-scale access patterns that won’t be visible if only basic login history logs are collected. Additional Salesforce telemetry that captures logins, configuration changes, connected app/API activity, and export behavior is needed to investigate SaaS-native exfiltration. Detailed implementation guidance for these visibility gaps can be found in Mandiant’s Targeted Logging and Detection Controls for Salesforce.

What You Need in Place Before Logging

• Entitlement check (must-have)
  • Most security-relevant Salesforce logs are gated behind Event Monitoring, delivered through Salesforce Shield or the Event Monitoring add-on. Confirm you are licensed for the event types you plan to use for detection.
• Choose the collection method that matches your operations
  • Use real-time event monitoring (RTEM) if you need near real-time detection.
  • Use event log files (ELF) if you need predictable batch exports for long-term storage and retrospective investigations.
  • Use event log objects (ELO) if you require queryable history via Salesforce Object Query Language (often requires Shield/add-on).
• Enable the events you intend to detect on
  • Use Event Manager to explicitly turn on the event categories you plan to ingest, and ensure the right teams have access to view and operationalize the data (profiles/permission sets).
• Threat Detection and Enhanced Transaction Security
  • If your environment uses Threat Detection or ETS, verify the event types that feed those controls and ensure your log ingestion platform doesn’t omit the events you expect to alert on.

What to Enable and Ingest into the SIEM

Authentication and access

• LoginHistory (who logged in, when, from where, success/failure, client type)

• LoginEventStream (richer login telemetry where available)

Administrative/configuration visibility

• SetupAuditTrail (changes to admin and security configurations)

API and export visibility

• ApiEventStream (API usage by users and connected apps)

• ReportEventStream (report export/download activity)

• BulkApiResultEvent (bulk job result downloads—critical for bulk extraction visibility)

Additional high-value sources (if available in your tenant)

• LoginAsEventStream (impersonation / “login as” activity)

• PermissionSetEvent (permission grants/changes)

SaaS Pivot Logging 

Threat actors often pivot from compromised SSO providers into additional SaaS platforms, including DocuSign and Atlassian. Ingesting audit logs from these platforms into a SIEM environment enables the detection of suspicious access and large-scale data exfiltration following an identity compromise.

What You Need in Place Before Logging

• You need tenant-level admin permissions to access and configure audit/event logging.

• Confirm your plan/subscriptions include the audit/event visibility you are trying to collect (Atlassian org audit log capabilities can depend on plan/Guard tier; DocuSign org-level activity monitoring is provided via DocuSign Monitor).

• API access (If you are pulling logs programmatically): Ensure the tenant is able to use the vendor’s audit/event APIs (DocuSign Monitor API; Atlassian org audit log API/webhooks depending on capability).

• Retention reality check: Validate the platform’s native audit-log retention window meets your investigation needs.

What to Enable and Ingest into the SIEM

DocuSign (audit/monitoring logs)

• Authentication events (successful/failed sign-ins, SSO vs password login if available)

• Administrative changes (user/role changes, org-level setting changes)

• Envelope access and bulk activity (envelope viewed/downloaded, document downloaded, bulk send, bulk download/export where available)

• API activity (API calls, integration keys/apps used, client/app identifiers)

• Source context (source IP/geo, user agent/client type)

Atlassian (Jira/Confluence audit logs)

• Authentication events (SSO sign-ins, failed logins)

• Privilege and admin changes (role/group membership changes, org admin actions)

• Confluence/Jira data access at scale:

• Confluence: space/page view/download/export events (especially exports)

• Jira: project access, issue export, bulk actions (where available)

• API token and app activity (API token created/revoked, OAuth app connected, marketplace app install/uninstall)

• Source context (source IP/geolocation, user agent/client type)

Microsoft 365 Audit Logging 

Mandiant has observed threat actors leveraging PowerShell to download sensitive data from SharePoint and OneDrive as part of this campaign. To detect the activity, it is necessary to ingest M365 audit telemetry that records file download operations along with client context (especially the user agent).

What You Need in Place Before Logging

• Microsoft Purview Audit is available and enabled: Your tenant must have Microsoft Purview Audit turned on and usable (Audit “Standard” vs “Premium” affects capabilities/retention).

• Correct permissions to view/search audit: Assign the compliance/audit roles required to access audit search and records.

• SharePoint/OneDrive operations are present in the Unified Audit Log: Validate that SharePoint/OneDrive file operations are being recorded (this is where operations like file download/access show up).

• Client context is captured: Confirm audit records include UserAgent (when provided by the client) so you can identify PowerShell-based access patterns in SharePoint/OneDrive activity.

What to Enable and Ingest into the SIEM

• FileDownloaded and FileAccessed (SharePoint/OneDrive)

• User agent/client identifier (to surface WindowsPowerShell-style user agents)

• User identity, source IP, geolocation

• Target resource details

3. Detections

The following detections target behavioral patterns Mandiant has identified in ShinyHunters related intrusions. In these scenarios, attackers typically gain initial access by compromising SSO platforms or manipulating MFA controls, then leverage native SaaS capabilities to exfiltrate data and evade detection.The following use cases are categorized by area of focus, including Identity Providers and Productivity Platforms. 

Note: This activity is not the result of a security vulnerability in vendors' products or infrastructure. Instead, these intrusions rely on the effectiveness of ShinyHunters related intrusions.

Implementation Guidelines

These rules are presented as YARA-L pseudo-code to prioritize clear detection logic and cross-platform portability. Because field names, event types, and attribute paths vary across environments, consider the following variables:

• Ingestion Source: Differences in how logs are ingested into Google SecOps.

• Parser Mapping: Specific UDM (Unified Data Model) mappings unique to your configuration.

• Telemetry Availability: Variations in logging levels based on your specific SaaS licensing.

• Reference Lists: Curated allowlists/blocklists the organization will need to create to help reduce noise and keep alerts actionable.

Note: Mandiant recommends testing these detections prior to deployment by validating the exact event mappings in your environment and updating the pseudo-fields to match your specific telemetry.

Okta

MFA Device Enrollment or Changes (Post-Vishing Signal)

Detects MFA device enrollment and MFA life cycle changes that often occur immediately after a social-engineered account takeover. When this alert is triggered, immediately review the affected user’s downstream access across SaaS applications (Salesforce, Google Workspace, Atlassian, DocuSign, etc.) for signs of large-scale access or data exports.

Why this is high-fidelity: In this intrusion pattern, MFA manipulation is a primary “account takeover” step. Because MFA lifecycle events are rare compared to routine logins, any modification occurring shortly after access is gained serves as a high-fidelity indicator of potential compromise.

Key signals

• Okta system Log MFA lifecycle events (enroll/activate/deactivate/reset)

• principal.user, principal.ip, client.user_agent, geolocation/ASN (if enriched)

• Optional: proximity to password reset, recovery, or sign-in anomalies (same user, short window)

Pseudo-code (YARA-L)

events:
$mfa.metadata.vendor_name = "Okta"
$mfa.metadata.product_event_type in ( "okta.user.mfa.factor.enroll", "okta.user.mfa.factor.activate",  "okta.user.mfa.factor.deactivate", "okta.user.mfa.factor.reset_all" )
$u= $mfa.principal.user.userid
$t_mfa = $mfa.metadata.event_timestamp

$ip = coalesce($mfa.principal.ip, $mfa.principal.asset.ip)
$ua = coalesce($mfa.network.http.user_agent, $mfa.extracted.fields["userAgent"], "") 

$reset.metadata.vendor_name = "Okta"
$reset.metadata.product_event_type in (
"okta.user.password.reset",  "okta.user.account.recovery.start" )
$t_reset = $reset.metadata.event_timestamp

$auth.metadata.vendor_name = "Okta"
$auth.metadata.product_event_type in ("okta.user.authentication.sso", "okta.user.session.start")
$t_auth = $auth.metadata.event_timestamp

match:
$u over 30m

condition:
// Always alert on MFA lifecycle change
$mfa and
// Optional sequence tightening (enrichment only, not mandatory):
// If reset/auth exists in the window, enforce it happened before the MFA change.
(
(not $reset and not $auth) or
(($reset and $t_reset < $t_mfa) or ($auth and $t_auth < $t_mfa))
)

Suspicious admin.security Actions from Anonymized IPs

Alert on Okta admin/security posture changes when the admin action occurs from suspicious network context (proxy/VPN-like indicators) or immediately after an unusual auth sequence.

Why this is high-fidelity: Admin/security control changes are low volume and can directly enable persistence or reduce visibility.

Key signals

• Okta admin/system events (e.g., policy changes, MFA policy, session policy, admin app access)

• “Anonymized” network signal: VPN/proxy ASN, “datacenter” reputation, TOR list, etc.

• Actor uses unusual client/IP for admin activity

Reference lists

• VPN_TOR_ASNS (proxy/VPN ASN list)

Pseudo-code (YARA-L)

events:
$a.metadata.vendor_name = "Okta"
$a.metadata.product_event_type in ("okta.system.policy.update","okta.system.security.change","okta.user.session.clear","okta.user.password.reset","okta.user.mfa.reset_all")  
userid=$a.principal.user.userid
// correlate with a recent successful login for the same actor if available
$l.metadata.vendor_name = "Okta"
$l.metadata.product_event_type = "okta.user.authentication.sso"
userid=$l.principal.user.userid

match:
userid over 2h

condition:
$a and $l

Google Workspace

OAuth Authorization for ToogleBox Recall

Detects OAuth/app authorization events for ToogleBox recall (or the known app identifier), indicating mailbox manipulation activity.

Why this is high-fidelity: This is a tool-specific signal tied to the observed “delete security notification emails” behavior.

Key signals

• Workspace OAuth / token authorization log event

• App name, app ID, scopes granted, granting user, source IP/geo

• Optional: privileged user context (e.g., admin, exec assistant)

Pseudo-code (YARA-L)

events:
$e.metadata.vendor_name = "Google Workspace"
$e.metadata.product_event_type in ("gws.oauth.grant", "gws.token.authorize") // placeholders
// match app name OR app id if you have it
(lower($e.target.application) contains "tooglebox" or
lower($e.target.application) contains "recall")
condition:
$e

Gmail Deletion of Okta Security Notification Email

Detects deletion actions targeting Okta security notification emails (e.g., “Security method enrolled”).

Why this is high-fidelity: Targeted deletion of security notifications is intentional evasion, not normal email behavior.

Key signals

• Gmail audit log delete/permanent delete (or mailbox cleanup) event

• Subject matches a small set of security-notification strings

• Time correlation: deletion shortly after receipt (optional)

Pseudo-code (YARA-L)

events:
$d.metadata.vendor_name = "Google Workspace"
$d.metadata.product_event_type in ("gws.gmail.message.delete",
                                       "gws.gmail.message.trash",
                                       "gws.gmail.message.permanent_delete") // PLACEHOLDER
regex_match(lower($d.target.email.subject),
"(security method enrolled|new sign-in|new device|mfa|authentication|verification)")
$u = $d.principal.user.userid
$t = $d.metadata.event_timestamp

match:
$u over 30m

condition:
$d and count($d) >= 2   // tighten: at least 2 in 30m; adjust if too strict
}

Google Takeout Export Initiated/Completed

Detects Google Takeout export initiation/completion events.

Why this is high-fidelity: Takeout exports are uncommon in corporate contexts; in this campaign they represent a direct data export path.

Key signals

• Takeout audit events (e.g., initiated, completed)

• User, source IP/geo, volume

Reference lists

• TAKEOUT_ALLOWED_USERS (rare; HR offboarding workflows, legal export workflows)

Pseudo-code (YARA-L)

events:
$start.metadata.vendor_name = "Google Workspace"
$start.metadata.product_event_type = "gws.takeout.export.start"      
$user = $start.principal.user.userid
$job  = $start.target.resource.id   // if available; otherwise remove job join

$done.metadata.vendor_name = "Google Workspace"
$done.metadata.product_event_type  = "gws.takeout.export.complete"   
$bytes = coalesce($done.target.file.size, $done.extensions.bytes_exported)

match:
// takeout can take hours; don't use 10m here, adjust accordingly
$start.principal.user.userid = $done.principal.user.userid over 24h
// if you have a job/export id, this makes it *much* cleaner
$start.target.resource.id = $done.target.resource.id
condition:
$start and $done and
$start.metadata.event_timestamp < $done.metadata.event_timestamp and
$bytes >= 500000000   // 500MB start point; tune
not ($u in %TAKEOUT_ALLOWED_USERS) // OPTIONAL: remove if you don't maintain it

Cross-SaaS

Attempted Logins from Known Campaign Proxy/IOC Networks

Detects authentication attempts across SaaS/SSO providers originating from IPs/ASNs associated with the campaign.

Why this is high-fidelity: These IPs and ASNs lack legitimate business overlap; matches indicate direct interaction between compromised credentials and known adversary-controlled infrastructure.

Key signals

• Authentication attempts across Okta / Salesforce / Workspace / Atlassian / DocuSign

• principal.ip matches IOC IPs or ASN list

Reference lists

• SHINYHUNTERS_PROXY_IPS

• VPN_TOR_ASNS

Pseudo-code (YARA-L)

events:
$e.metadata.product_event_type in (
      "okta.login.attempt", "workday.sso.login.attempt",
      "gws.login.attempt",  "salesforce.login.attempt",
      "atlassian.login.attempt", "docusign.login.attempt"
    ) 
(
      $e.principal.ip in %SHINYHUNTERS_PROXY_IPS or
      $e.principal.ip.asn in %VPN_TOR_ASNS
)

condition:
$e

Identity Activity Outside Normal Business Hours

Detects identity events occurring outside normal business hours, focusing on high-risk actions (sign-ins, password reset, new MFA enrollment and/or device changes).

Why this is high-fidelity: A strong indication of abnormal user behavior when also constrained to sensitive actions and users who rarely perform them.

Key signals

• User sign-ins, password resets, MFA enrollment, device registrations

• Timestamp bucket: late evening / friday afternoon / weekends

Pseudo-code (YARA-L)

events:
$e.metadata.vendor_name = "Okta"
$e.metadata.product_event_type in ("okta.user.password.reset","okta.user.mfa.factor.activate","okta.user.mfa.factor.reset_all") // PLACEHOLDER
outside_business_hours($e.metadata.event_timestamp, "America/New_York") 
// Include the business hours your organization functions in
$u = $e.principal.user.userid

condition:
$e

Successful Sign-in From New Location and New MFA Method

Detects a successful login that is simultaneously from a new geolocation and uses a newly registered MFA method.

Why this is high-fidelity: This pattern represents a compound condition that aligns with MFA manipulation and unfamiliar access context.

Key signals

• Successful authentication

• New geolocation compared to user baseline

• New factor method compared to user baseline (or recent MFA enrollment)

• Optional sequence: MFA enrollment occurs after login

Pseudo-code (YARA-L)

events:
$login.metadata.vendor_name = "Okta"
$login.metadata.product_event_type = "okta.login.success" 
$u = $login.principal.user.userid
$geo = $login.principal.location.country
$t_l = $login.metadata.event_timestamp
$m = $login.security_result.auth_method // if present; otherwise join to factor event

condition:
$login and
first_seen_country_for_user($u, $geo) and
first_seen_factor_for_user($u, $m)

Multiple MFA Enrollments Across Different Users From the Same Source IP

Detects the same source IP enrolling/changing MFA for multiple users in a short window.

Why this is high-fidelity:This pattern mirrors a known social engineering tactic where threat actors manipulate help desk admins to enroll unauthorized devices into a victim’s MFA - spanning multiple users from the same source address

Key signals

• Okta MFA lifecycle events

• Same src_ip

• Distinct user count threshold

• Tight window

Pseudo-code (YARA-L)

events:
$m.metadata.vendor_name = "Okta"
$m.metadata.product_event_type in ("<OKTA_MFA_ENROLL_EVENT>", "<OKTA_MFA_DEVICE_ENROLL_EVENT>") 
$ip  = coalesce($m.principal.ip, $m.principal.asset.ip)
$uid = $m.principal.user.userid

match:
$ip over 10m

condition:
count_distinct($uid) >= 3

Network

Web/DNS Access to Credential Harvesting, Portal Impersonation Domains

Detects DNS queries or HTTP referrers matching brand and SSO/login keyword lookalike patterns.

Why this is high-fidelity: Captures credential-harvesting infrastructure patterns when you have network telemetry.

Key signals

• DNS question name or HTTP referrer/URL

• Regex match for brand + SSO keywords

• Exclusions for your legitimate domains

Reference lists

• Allowlist (small) of legitimate domains (optional)

Pseudo-code (YARA-L)

events:
$event.metadata.event_type in ("NETWORK_HTTP", "NETWORK_DNS")
// pick ONE depending on which log source you're using most
// DNS:
$domain = lower($event.network.dns.questions.name)
// If you’re using HTTP instead, swap the line above to:
// $domain = lower($event.network.http.referring_url)

condition:
regex_match($domain, ".*(yourcompany(my|sso|internal|okta|access|azure|zendesk|support)|(my|sso|internal|okta|access|azure|zendesk|support)yourcompany).*"
)
and not regex_match($domain, ".*yourcompany\\.com.*")
and not regex_match($domain, ".*okta\\.yourcompany\\.com.*")

Microsoft 365

M365 SharePoint/OneDrive: FileDownloaded with WindowsPowerShell User Agent

Detects SharePoint/OneDrive downloads with PowerShell user-agent that exceed a byte threshold or count threshold within a short window.

Why this is high-fidelity: PowerShell-driven SharePoint downloading and burst volume indicates scripted retrieval.

Key signals

• FileDownloaded/FileAccessed

• User agent contains PowerShell

• Bytes transferred OR number of downloads in window

• Timestamp window (ordering implicit) and min<max check

Pseudo-code (YARA-L)

events:
  $e.metadata.vendor_name = "Microsoft"
  (
    $e.target.application = "SharePoint" or
    $e.target.application = "OneDrive"
  )
  $e.metadata.product_event_type = /FileDownloaded|FileAccessed/
  $e.network.http.user_agent = /PowerShell/ nocase
  $user = $e.principal.user.userid
  $bytes = coalesce($e.target.file.size, $e.extensions.bytes_transferred) 
  $ts = $e.metadata.event_timestamp

match:
  $user over 15m

condition:
  // keep your PowerShell constraint AND require volume
  $e and (sum($bytes) >= 500000000 or count($e) >= 20) and min($ts) < max($ts)

M365 SharePoint: High Volume Document FileAccessed Events

Detects SharePoint document file access events that exceed a count threshold and minimum unique file types within a short window.

Why this is high-fidelity: Burst volume may indicate scripted retrieval or usage of the Open-in-App feature within SharePoint.

Key signals

• FileAccessed

• Filtering on common document file types (e.g., PDF) 

• Number of downloads in window

• Minimum unique file types

Pseudo-code (YARA-L)

events:
  $e.metadata.vendor_name = "Microsoft"
  $e.metadata.product_event_type = "FileAccessed"
  $e.target.application = "SharePoint"
  $e.target.file.full_path = /\.(doc[mx]?|xls[bmx]?|ppt[amx]?|pdf)$/ nocase)
  $file_extension_extract = re.capture($e.target.file.full_path, `\.([^\.]+)$`)
  $session_id = $e.network.session_id

match:
  $session_id over 5m

outcome:
  $target_url_count = count_distinct(strings.coalesce($e.target.file.full_path))
  $extension_count = count_distinct($file_extension_extract)

condition:
  $e and $target_url_count >= 50 and $extension_count >= 3

M365 SharePoint: High Volume Document FileDownloaded Events

Detects SharePoint document file downloaded events that exceed a count threshold and minimum unique file types within a short window.

Why this is high-fidelity: Burst volume may indicate scripted retrieval, which may also be generated by legitimate backup processes.

Key signals

• FileDownloaded

• Filtering on common document file types (e.g., PDF) 

• Number of downloads in window

• Minimum unique file types

Pseudo-code (YARA-L)

events:
  $e.metadata.vendor_name = "Microsoft"
  $e.metadata.product_event_type = "FileDownloaded"
  $e.target.application = "SharePoint"
  $e.target.file.full_path = /\.(doc[mx]?|xls[bmx]?|ppt[amx]?|pdf)$/ nocase)
  $file_extension_extract = re.capture($e.target.file.full_path, `\.([^\.]+)$`)
  $session_id = $e.network.session_id

match:
  $session_id over 5m

outcome:
  $target_url_count = count_distinct(strings.coalesce($e.target.file.full_path))
  $extension_count = count_distinct($file_extension_extract)

condition:
  $e and $target_url_count >= 50 and $extension_count >= 3

M365 SharePoint: Query for Strings of Interest

Detects SharePoint queries for files relating to strings of interest, such as sensitive documents, clear-text credentials, and proprietary information.

Why this is high-fidelity: Multiple searches for strings of interest by a single account occurs infrequently. Generally, users will search for project or task specific strings rather than general labels (e.g., “confidential”).

Key signals

• SearchQueryPerformed

• Filtering on strings commonly associated with sensitive or privileged information 

Pseudo-code (YARA-L)

events:
  $e.metadata.vendor_name = "Microsoft"
  $e.metadata.product_event_type = "SearchQueryPerformed"
  $e.target.application = "SharePoint"
  $e.additional.fields["search_query_text"] = /\bpoc\b|proposal|confidential|internal|salesforce|vpn/ nocase

condition:
  $e

M365 Exchange Deletion of MFA Modification Notification Email

Detects deletion actions targeting Okta and other platform security notification emails (e.g., “Security method enrolled”).

Why this is high-fidelity: Targeted deletion of security notifications can be intentional evasion and is not typically performed by email users.

Key signals

• M365 Exchange audit log delete/permanent delete (or mailbox cleanup) event

• Subject matches a small set of security-notification strings

• Time correlation: deletion shortly after receipt (optional)

Pseudo-code (YARA-L)

events:
  $e.metadata.vendor_name = "Microsoft"
  $e.target.application = "Exchange"
  $e.metadata.product_event_type = /^(SoftDelete|HardDelete|MoveToDeletedItems)$/ nocase
  $e.network.email.subject = /new\s+(mfa|multi-|factor|method|device|security)|\b2fa\b|\b2-Step\b|(factor|method|device|security|mfa)\s+(enroll|registered|added|change|verify|updated|activated|configured|setup)/ nocase

  // filtering specifically for new device registration strings
  $e.network.email.subject = /enroll|registered|added|change|verify|updated|activated|configured|setup/ nocase

  // tuning out new device logon events
  $e.network.email.subject != /(sign|log)(-|\s)?(in|on)/ nocase

condition:
  $e

Introduction 

Mandiant has identified an expansion in threat activity that uses tactics, techniques, and procedures (TTPs) consistent with prior ShinyHunters-branded extortion operations. These operations primarily leverage sophisticated voice phishing (vishing) and victim-branded credential harvesting sites to gain initial access to corporate environments by obtaining single sign-on (SSO) credentials and multi-factor authentication (MFA) codes. Once inside, the threat actors target cloud-based software-as-a-service (SaaS) applications to exfiltrate sensitive data and internal communications for use in subsequent extortion demands.

Google Threat Intelligence Group (GTIG) is currently tracking this activity under multiple threat clusters (UNC6661, UNC6671, and UNC6240) to enable a more granular understanding of evolving partnerships and account for potential impersonation activity. While this methodology of targeting identity providers and SaaS platforms is consistent with our prior observations of threat activity preceding ShinyHunters-branded extortion, the breadth of targeted cloud platforms continues to expand as these threat actors seek more sensitive data for extortion. Further, they appear to be escalating their extortion tactics with recent incidents including harassment of victim personnel, among other tactics.

This activity is not the result of a security vulnerability in vendors' products or infrastructure. Instead, it continues to highlight the effectiveness of social engineering and underscores the importance of organizations moving towards phishing-resistant MFA where possible. Methods such as FIDO2 security keys or passkeys are resistant to social engineering in ways that push-based or SMS authentication are not.

Mandiant has also published a comprehensive guide with proactive hardening and detection recommendations, and Google published a detailed walkthrough for operationalizing these findings within Google Security Operations.

UNC6661 Vishing and Credential Theft Activity

In incidents spanning early to mid-January 2026, UNC6661 pretended to be IT staff and called employees at targeted victim organizations claiming that the company was updating MFA settings. The threat actor directed the employees to victim-branded credential harvesting sites to capture their SSO credentials and MFA codes, and then registered their own device for MFA. The credential harvesting domains attributed to UNC6661 commonly, but not exclusively, use the format <companyname>sso.com or <companyname>internal.com and have often been registered with NICENIC.

In at least some cases, the threat actor gained access to accounts belonging to Okta customers. Okta published a report about phishing kits targeting identity providers and cryptocurrency platforms, as well as follow-on vishing attacks. While they associate this activity with multiple threat clusters, at least some of the activity appears to overlap with the ShinyHunters-branded operations tracked by GTIG.

After gaining initial access, UNC6661 moved laterally through victim customer environments to exfiltrate data from various SaaS platforms (log examples in Figures 2 through 5). While the targeting of specific organizations and user identities is deliberate, analysis suggests that the subsequent access to these platforms is likely opportunistic, determined by the specific permissions and applications accessible via the individual compromised SSO session. These compromises did not result from security vulnerabilities in the vendors' products or infrastructure.

In some cases, they have appeared to target specific types of information. For example, the threat actors have conducted searches in cloud applications for documents containing specific text including "poc," "confidential," "internal," "proposal," "salesforce," and "vpn" or targeted personally identifiable information (PII) stored in Salesforce. Additionally, UNC6661 may have targeted Slack data at some victims' environments, based on a claim made in a ShinyHunters-branded data leak site (DLS) entry.

{
  "AppAccessContext": {
    "AADSessionId": "[REDACTED_GUID]",
    "AuthTime": "1601-01-01T00:00:00",
    "ClientAppId": "[REDACTED_APP_ID]",
    "ClientAppName": "Microsoft Office",
    "CorrelationId": "[REDACTED_GUID]",
    "TokenIssuedAtTime": "1601-01-01T00:02:56",
    "UniqueTokenId": "[REDACTED_ID]"
  },
  "CreationTime": "2026-01-10T13:17:11",
  "Id": "[REDACTED_GUID]",
  "Operation": "FileDownloaded",
  "OrganizationId": "[REDACTED_GUID]",
  "RecordType": 6,
  "UserKey": "[REDACTED_USER_KEY]",
  "UserType": 0,
  "Version": 1,
  "Workload": "SharePoint",
  "ClientIP": "[REDACTED_IP]",
  "UserId": "[REDACTED_EMAIL]",
  "ApplicationId": "[REDACTED_APP_ID]",
  "AuthenticationType": "OAuth",
  "BrowserName": "Mozilla",
  "BrowserVersion": "5.0",
  "CorrelationId": "[REDACTED_GUID]",
  "EventSource": "SharePoint",
  "GeoLocation": "NAM",
  "IsManagedDevice": false,
  "ItemType": "File",
  "ListId": "[REDACTED_GUID]",
  "ListItemUniqueId": "[REDACTED_GUID]",
  "Platform": "WinDesktop",
  "Site": "[REDACTED_GUID]",
  "UserAgent": "Mozilla/5.0 (Windows NT; Windows NT 10.0; en-US) WindowsPowerShell/5.1.20348.4294",
  "WebId": "[REDACTED_GUID]",
  "DeviceDisplayName": "[REDACTED_IPV6]",
  "EventSignature": "[REDACTED_SIGNATURE]",
  "FileSizeBytes": 31912,
  "HighPriorityMediaProcessing": false,
  "ListBaseType": 1,
  "ListServerTemplate": 101,
  "SensitivityLabelId": "[REDACTED_GUID]",
  "SiteSensitivityLabelId": "",
  "SensitivityLabelOwnerEmail": "[REDACTED_EMAIL]",
  "SourceRelativeUrl": "[REDACTED_RELATIVE_URL]",
  "SourceFileName": "[REDACTED_FILENAME]",
  "SourceFileExtension": "xlsx",
  "ApplicationDisplayName": "Microsoft Office",
  "SiteUrl": "[REDACTED_URL]",
  "ObjectId": "[REDACTED_URL]/[REDACTED_FILENAME]"
}

Figure 2: SharePoint/M365 log example

"Login","20260120163111.430","SLB:[REDACTED]","[REDACTED]","[REDACTED]","192","25","/index.jsp","","1jVcuDh1VIduqg10","Standard","","167158288","5","Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/IP_ADDRESS_REMOVED Safari/537.36","","9998.0","user@[REDACTED_DOMAIN].com","TLSv1.3","TLS_AES_256_GCM_SHA384","","https://[REDACTED_IDP_DOMAIN]/","[REDACTED].my.salesforce.com","CA","","","0LE1Q000000LBVK","2026-01-20T16:31:11.430Z","[REDACTED]","76.64.54[.]159","","LOGIN_NO_ERROR","76.64.54[.]159",""

Figure 3: Salesforce log example

{
  "Timestamp": "2026-01-21T12:5:2-03:00",
  "Timestamp UTC": "[REDACTED]",
  "Event Name": "User downloads documents from an envelope",
  "Event Id": "[REDACTED_EVENT_ID]",
  "User": "[REDACTED]@example.com",
  "User Id": "[REDACTED_USER_ID]",
  "Account": "[REDACTED_ORG_NAME]",
  "Account Id": "[REDACTED_ACCOUNT_ID]",
  "Integrator Key": "[REDACTED_KEY]",
  "IP Address": "73.135.228[.]98",
  "Latitude": "[REDACTED]",
  "Longitude": "[REDACTED]",
  "Country/Region": "United States",
  "State": "Maryland",
  "City": "[REDACTED]",
  "Browser": "Chrome 143",
  "Device": "Apple Mac",
  "Operating System": "Mac OS X 10",
  "Source": "Web",
  "DownloadType": "Archived",
  "EnvelopeId": "[REDACTED_ENVELOPE_ID]"
}

Figure 4: Docusign log example

In at least one incident where the threat actor gained access to an Okta customer account, UNC6661 enabled the ToogleBox Recall add-on for the victim's Google Workspace account, a tool designed to search for and permanently delete emails. They then deleted a "Security method enrolled" email from Okta, almost certainly to prevent the employee from identifying that their account was associated with a new MFA device.

{
  "Date": "2026-01-11T06:3:00Z",
  "App ID": "[REDACTED_ID].apps.googleusercontent.com",
  "App name": "ToogleBox Recall",
  "OAuth event": "Authorize",
  "Description": "User authorized access to ToogleBox Recall for specific Gmail and Apps Script scopes.",
  "User": "user@[REDACTED_DOMAIN].com",
  "Scope": "https://www.googleapis.com/auth/gmail.addons.current.message.readonly, https://www.googleapis.com/auth/gmail.addons.execute, https://www.googleapis.com/auth/script.external_request, https://www.googleapis.com/auth/script.locale, https://www.googleapis.com/auth/userinfo.email",
  "API name": "",
  "Method": "",
  "Number of response bytes": "0",
  "IP address": "149.50.97.144",
  "Product": "Gmail, Apps Script Runtime, Apps Script Api, Identity, Unspecified",
  "Client type": "Web",
  "Network info": "{\n  \"Network info\": {\n    \"IP ASN\": \"201814\",\n    \"Subdivision code\": \"\",\n    \"Region code\": \"PL\"\n  }\n}"
}

Figure 5: ToogleBox Recall auth log entry example

In at least one case, after conducting the initial data theft, UNC6661 used their newly obtained access to compromised email accounts to send additional phishing emails to contacts at cryptocurrency-focused companies. The threat actor then deleted the outbound emails, likely in an attempt to obfuscate their malicious activity.

GTIG attributes the subsequent extortion activity following UNC6661 intrusions to UNC6240, based on several overlaps, including the use of a common Tox account for negotiations, ShinyHunters-branded extortion emails, and Limewire to host samples of stolen data. In mid-January 2026 extortion emails, UNC6240 outlined what data they allegedly stole, specifying a payment amount and destination BTC address, and threatening consequences if the ransom was not paid within 72 hours, which is consistent with prior extortion emails (Figure 6). They also provided proof of data theft via samples hosted on Limewire. GTIG also observed extortion text messages sent to employees and received reports of victim websites being targeted with distributed denial-of-service (DDoS) attacks.

Notably, in late January 2026 a new ShinyHunters-branded DLS named "SHINYHUNTERS" emerged listing several alleged victims who may have been compromised in these most recent extortion operations. The DLS also lists contact information (shinycorp@tutanota[.]com, shinygroup@onionmail[.]com) that have previously been associated with UNC6240.

Similar Activity Conducted by UNC6671

Also beginning in early January 2026, UNC6671 conducted vishing operations masquerading as IT staff and directing victims to enter their credentials and MFA authentication codes on a victim-branded credential harvesting site. The credential harvesting domains used the same structure as UNC6661, but were more often registered using Tucows. In at least some cases, the threat actors have gained access to Okta customer accounts. Mandiant has also observed evidence that UNC6671 leveraged PowerShell to download sensitive data from SharePoint and OneDrive. While many of these TTPs are consistent with UNC6661, an extortion email stemming from UNC6671 activity was unbranded and used a different Tox ID for further contact. The threat actors employed aggressive extortion tactics following UNC6671 intrusions, including harassment of victim personnel. The extortion tactics and difference in domain registrars suggests that separate individuals may be involved with these sets of activity.

Remediation and Hardening

Mandiant has published a comprehensive guide with proactive hardening and detection recommendations.

Outlook and Implications

This recent activity is similar to prior operations associated with UNC6240, which have frequently used vishing for initial access and have targeted Salesforce data. It does, however, represent an expansion in the number and type of targeted cloud platforms, suggesting that the associated threat actors are modifying their operations to gather more sensitive data for extortion operations. Further, the use of a compromised account to send phishing emails to cryptocurrency-related entities suggests that associated threat actors may be building relationships with potential victims to expand their access or engage in other follow-on operations. Notably, this portion of the activity appears operationally distinct, given that it appears to target individuals instead of organizations.

Indicators of Compromise (IOCs)

To assist the wider community in hunting and identifying activity outlined in this blog post, we have included indicators of compromise (IOCs) in a free GTI Collection for registered users.

Phishing Domain Lure Patterns 

Threat actors associated with these clusters frequently register domains designed to impersonate legitimate corporate portals. At time of publication all identified phishing domains have been added to Chrome Safe Browsing. These domains typically follow specific naming conventions using a variation of the organization name:

Network Indicators

Many of the network indicators identified in this campaign are associated with commercial VPN services or residential proxy networks, including Mullvad, Oxylabs, NetNut, 9Proxy, Infatica, and nsocks. Mandiant recommends that organizations exercise caution when using these indicators for broad blocking and prioritize them for hunting and correlation within their environments.

Google Security Operations

Google Security Operations customers have access to these broad category rules and more under the Okta, Cloud Hacktool, and O365 rule packs. A walkthrough for operationalizing these findings within the Google Security Operations is available in Part Three of this series. The activity discussed in the blog post is detected in Google Security Operations under the rule names:

• Okta Admin Console Access Failure

• Okta Super or Organization Admin Access Granted

• Okta Suspicious Actions from Anonymized IP

• Okta User Assigned Administrator Role

• O365 SharePoint Bulk File Access or Download via PowerShell

• O365 SharePoint High Volume File Access Events

• O365 SharePoint High Volume File Download Events

• O365 Sharepoint Query for Proprietary or Privileged Information

• O365 Deletion of MFA Modification Notification Email

• Workspace ToogleBox Recall OAuth Application Authorized

 $e.metadata.product_name = "Okta"
    $e.metadata.product_event_type = /\.(add|update_|(policy.rule|zone)\.update|create|register|(de)?activate|grant|reset_all|user.session.access_admin_app)$/
    (
         $e.security_result.detection_fields["anonymized IP"] = "true" or
         $e.extracted.fields["debugContext.debugData.tunnels"] = /\"anonymous\":true/
    )
    $e.security_result.action = “ALLOW”

Figure 7: Hunting query for suspicious Okta actions conducted from anonymized IPs

$e.metadata.vendor_name = "Google Workspace"
   $e.metadata.event_type = "USER_RESOURCE_ACCESS"
   $e.metadata.product_event_type = "authorize"
   $e.target.resource.name = /ToogleBox Recall/ nocase

Figure 8: Hunting query for Google Workspace authorization events for ToogleBox Recall

$e.principal.ip_geo_artifact.network.organization_name = /mullvad.vpn|oxylabs|9proxy|netnut|infatica|nsocks/ nocase or
   $e.extracted.fields["debugContext.debugData.tunnels"] = /mullvad.vpn|oxylabs|9proxy|netnut|infatica|nsocks/ nocase

Figure 9: Hunting query for suspicious VPN / proxy services observed in this campaign

$e.network.http.user_agent = /Geny\s?Mobile/ nocase
   $event.security_result.action != "BLOCK"

Figure 10: Hunting query for suspicious user-agent string observed in this campaign

   $e.metadata.log_type = "OFFICE_365"   
  ($e.metadata.product_event_type = "FileDownloaded" or $e.metadata.product_event_type = "FileAccessed")
   (
     $e.target.application = "SharePoint" or
     $e.principal.application = "SharePoint"
   )
   $e.network.http.user_agent = /PowerShell/ nocase

Figure 11: Hunting query for programmatic file access or downloads from SharePoint where the User-Agent identifies as PowerShell

events:
   $e.metadata.log_type = "OFFICE_365"   
   $e.metadata.product_event_type = "FileAccessed"
   (
     $e.target.application = "SharePoint" or
     $e.principal.application = "SharePoint"
   )
   $e.target.file.full_path = /\.(doc[mx]?|xls[bmx]?|ppt[amx]?|pdf)$/ nocase
   $file_extension_extract = re.capture($e.target.file.full_path, `\.([^\.]+)$`)
   $event.security_result.action != "BLOCK"
   $session_id = $e.network.session_id

 match:
    $session_id over 5m

outcome:
   $target_url_count = count_distinct(strings.coalesce($e.target.file.full_path))
   $extension_count = count_distinct($file_extension_extract)

condition:
   $e and $target_url_count >= 50 and $extension_count >= 3

Figure 12: Hunting query for high volume document file access from SharePoint

events:
   $e.metadata.log_type = "OFFICE_365"   
   $e.metadata.product_event_type = "FileDownloaded"
   (
     $e.target.application = "SharePoint" or
     $e.principal.application = "SharePoint"
   )
   $e.target.file.full_path = /\.(doc[mx]?|xls[bmx]?|ppt[amx]?|pdf)$/ nocase
   $file_extension_extract = re.capture($e.target.file.full_path, `\.([^\.]+)$`)
   $event.security_result.action != "BLOCK"
   $session_id = $e.network.session_id

 match:
    $session_id over 5m

outcome:
   $target_url_count = count_distinct(strings.coalesce($e.target.file.full_path))
   $extension_count = count_distinct($file_extension_extract)

condition:
   $e and $target_url_count >= 50 and $extension_count >= 3

Figure 13: Hunting query for high volume document file downloads from SharePoint

$e.metadata.log_type = "OFFICE_365"   
   $e.metadata.product_event_type = "SearchQueryPerformed"
   $e.additional.fields["search_query_text"] = /\bpoc\b|proposal|confidential|internal|salesforce|vpn/ nocase

Figure 14: Hunting query for SharePoint queries for strings of interest

$e.metadata.log_type = "OFFICE_365"   
   $e.target.application = "Exchange"
   $e.metadata.product_event_type = /^(SoftDelete|HardDelete|MoveToDeletedItems)$/ nocase
   $e.network.email.subject = /new\s+(mfa|multi-|factor|method|device|security)|\b2fa\b|\b2-Step\b|(factor|method|device|security|mfa)\s+(enroll|registered|added|change|verify|updated|activated|configured|setup)/ nocase

   // filtering specifically for new device registration strings
   $e.network.email.subject = /enroll|registered|added|change|verify|updated|activated|configured|setup/ nocase
    
   // tuning out new device logon events
   $e.network.email.subject != /(sign|log)(-|\s)?(in|on)/ nocase

Figure 15: Hunting query for O365 Exchange deletion of MFA modification notification email

Introduction 

This week Google and partners took action to disrupt what we believe is one of the largest residential proxy networks in the world, the IPIDEA proxy network. IPIDEA’s proxy infrastructure is a little-known component of the digital ecosystem leveraged by a wide array of bad actors.

This disruption, led by Google Threat Intelligence Group (GTIG) in partnership with other teams, included three main actions:

1. Took legal action to take down domains used to control devices and proxy traffic through them.

2. Shared technical intelligence on discovered IPIDEA software development kits (SDKs) and proxy software with platform providers, law enforcement, and research firms to help drive ecosystem-wide awareness and enforcement. These SDKs, which are offered to developers across multiple mobile and desktop platforms, surreptitiously enroll user devices into the IPIDEA network. Driving collective enforcement against these SDKs helps protect users across the digital ecosystem and restricts the network's ability to expand.

3. These efforts to help keep the broader digital ecosystem safe supplement the protections we have to safeguard Android users on certified devices. We ensured Google Play Protect, Android’s built-in security protection, automatically warns users and removes applications known to incorporate IPIDEA SDKs, and blocks any future install attempts.

We believe our actions have caused significant degradation of IPIDEA’s proxy network and business operations, reducing the available pool of devices for the proxy operators by millions. Because proxy operators share pools of devices using reseller agreements, we believe these actions may have downstream impact across affiliated entities.

Dizzying Array of Bad Behavior Enabled by Residential Proxies

In contrast to other types of proxies, residential proxy networks sell the ability to route traffic through IP addresses owned by internet service providers (ISPs) and used to provide service to residential or small business customers. By routing traffic through an array of consumer devices all over the world, attackers can mask their malicious activity by hijacking these IP addresses. This generates significant challenges for network defenders to detect and block malicious activities.

A robust residential proxy network requires the control of millions of residential IP addresses to sell to customers for use. IP addresses in countries such as the US, Canada, and Europe are considered especially desirable. To do this, residential proxy network operators need code running on consumer devices to enroll them into the network as exit nodes. These devices are either pre-loaded with proxy software or are joined to the proxy network when users unknowingly download trojanized applications with embedded proxy code. Some users may knowingly install this software on their devices, lured by the promise of “monetizing” their spare bandwidth. When the device is joined to the proxy network, the proxy provider sells access to the infected device’s network bandwidth (and use of its IP address) to their customers. 

While operators of residential proxies often extol the privacy and freedom of expression benefits of residential proxies, Google Threat Intelligence Group’s (GTIG) research shows that these proxies are overwhelmingly misused by bad actors. IPIDEA has become notorious for its role in facilitating several botnets: its software development kits played a key role in adding devices to the botnets, and its proxy software was then used by bad actors to control them. This includes the BadBox2.0 botnet we took legal action against last year, and the Aisuru and Kimwolf botnets more recently. We also observe IPIDEA being leveraged by a vast array of espionage, crime, and information operations threat actors. In a single seven day period in January 2026, GTIG observed over 550 individual threat groups that we track utilizing IP addresses tracked as IPIDEA exit nodes to obfuscate their activities, including groups from China, DPRK, Iran and Russia. The activities included access to victim SaaS environments, on-premises infrastructure, and password spray attacks. Our research has found significant overlaps between residential proxy network exit nodes, likely because of reseller and partnership agreements, making definitive quantification and attribution challenging. 

In addition, residential proxies pose a risk to the consumers whose devices are joined to the proxy network as exit nodes. These users knowingly or unknowingly provide their IP address and device as a launchpad for hacking and other unauthorized activities, potentially causing them to be flagged as suspicious or blocked by providers. Proxy applications also introduce security vulnerabilities to consumers’ devices and home networks. When a user’s device becomes an exit node, network traffic that they do not control will pass through their device. This means bad actors can access a user’s private devices on the same network, effectively exposing security vulnerabilities to the internet. GTIG’s analysis of these applications confirmed that IPIDEA proxy did not solely route traffic through the exit node device, they also sent traffic to the device, in order to compromise it. While proxy providers may claim ignorance or close these security gaps when notified, enforcement and verification is challenging given intentionally murky ownership structures, reseller agreements, and diversity of applications.

The IPIDEA Proxy Network

Our analysis of residential proxy networks found that many well-known residential proxy brands are not only related but are controlled by the actors behind IPIDEA. This includes the following ostensibly independent proxy and VPN brands: 

• 360 Proxy (360proxy\.com)

• 922 Proxy (922proxy\.com)

• ABC Proxy (abcproxy\.com)

• Cherry Proxy (cherryproxy\.com)

• Door VPN (doorvpn\.com)

• Galleon VPN (galleonvpn\.com)

• IP 2 World (ip2world\.com)

• Ipidea (ipidea\.io)

• Luna Proxy (lunaproxy\.com)

• PIA S5 Proxy (piaproxy\.com)

• PY Proxy (pyproxy\.com)

• Radish VPN (radishvpn\.com)

• Tab Proxy (tabproxy\.com)

The same actors that control these brands also control several domains related to Software Development Kits (SDKs) for residential proxies. These SDKs are not meant to be installed or executed as standalone applications, rather they are meant to be embedded into existing applications. The operators market these kits as ways for developers to monetize their applications, and offer Android, Windows, iOS, and WebOS compatibility. Once developers incorporate these SDKs into their app, they are then paid by IPIDEA usually on a per-download basis.

Once the SDK is embedded into an application, it will turn the device it is running on into an exit node for the proxy network in addition to providing whatever the primary functionality of the application was. These SDKs are the key to any residential proxy network—the software they get embedded into provides the network operators with the millions of devices they need to maintain a healthy residential proxy network. 

While many residential proxy providers state that they source their IP addresses ethically, our analysis shows these claims are often incorrect or overstated. Many of the malicious applications we analyzed in our investigation did not disclose that they enrolled devices into the IPIDEA proxy network. Researchers have previously found uncertified and off-brand Android Open Source Project devices, such as television set top boxes, with hidden residential proxy payloads. 

The following SDKs are controlled by the same actors that control the IPIDEA proxy network:

• Castar SDK (castarsdk\.com)

• Earn SDK (earnsdk\.io)

• Hex SDK (hexsdk\.com)

• Packet SDK (packetsdk\.com)

Command-and-Control Infrastructure

We performed static and dynamic analysis on software that had SDK code embedded in it as well as standalone SDK files to identify the command-and-control (C2) infrastructure used to manage proxy exit nodes and route traffic through them. From the analysis we observed that EarnSDK, PacketSDK, CastarSDK, and HexSDK have significant overlaps in their C2 infrastructure as well as code structure.

Overview

The infrastructure model is a two-tier system: 

1. Tier One: Upon startup, the device will choose from a set of domains to connect to. The device sends some diagnostic information to the Tier One server and receives back a data payload that includes a set of Tier Two nodes to connect to.

2. Tier Two: The application will communicate directly with an IP address to periodically poll for proxy tasks. When it receives a proxy task it will establish a new dedicated connection to the Tier Two IP address and begin proxying the payloads it receives.

Tier One C2 Traffic

The device diagnostic information can be sent as HTTP GET query string parameters or in the HTTP POST body, depending on the domain and SDK. The payload sent includes a key parameter, which may be a customer identifier used to determine who gets paid for the device enrollment.

os=android&v=1.0.8&sn=993AE4FE78B879239BDC14DFBC0963CD&tag=OnePlus8Pro%23*%2311%23*%2330%23*%23QKR1.191246.002%23*%23OnePlus&key=cskfg9TAn9Jent&n=tlaunch

Figure 3: Sample device information send to Tier One server

The response from the Tier One server includes some timing information as well as the IP addresses of the Tier Two servers that this device should periodically poll for tasking.

{"code":200,"data":{"schedule":24,"thread":150,"heartbeat":20,"ip":[redacted],"info":"US","node":[{"net_type":"t","connect":"49.51.68.143:1000","proxy":"49.51.68.143:2000"},{"net_type":"t","connect":"45.78.214.188:800","proxy":"45.78.214.188:799"}]}

Figure 4: Sample response received from the Tier One Server

Tier Two C2 Traffic

The Tier Two servers are sent as connect and proxy pairs. In all analyses the pairs have been IP addresses, not domains. In our analysis, the pairs are the same IP address but different ports. The connect port is used to periodically poll for new proxy tasking. This is performed by sending TCP packets with encoded JSON payloads.

{"name": "0c855f87a7574b28df383eca5084fcdc", "o": "eDwSokuyOuMHcF10", "os": "windows"}

Figure 5: Sample encoded JSON sent to Tier Two connect port

When the Tier Two server has traffic to route to the device, it will respond back with the FQDN to proxy traffic to as well as a connection ID.

www.google.com:443&c8eb024c053f82831f2738bd48afc256

Figure 6: Sample proxy tasking from the Tier Two server

The device will then establish a connection to the proxy port of the same Tier Two server and send the connection ID, indicating that it is ready to receive data payloads.

8a9bd7e7a806b2cc606b7a1d8f495662|ok

Figure 7: Sample data sent from device to the Tier Two proxy port

The Tier Two server will then immediately send data payloads to be proxied. The device will extract the TCP data payload, establish a socket connection to the specified FQDN and send the payload, unmodified, to the destination. 

Overlaps in Infrastructure

The SDKs each have their own set of Tier One domains. This comes primarily from analysis of standalone SDK files. 

PacketSDK

• http://{random}.api-seed.packetsdk\.xyz

• http://{random}.api-seed.packetsdk\.net

• http://{random}.api-seed.packetsdk\.io

CastarSDK 

• dispatch1.hexsdk\.com

• cfe47df26c8eaf0a7c136b50c703e173\.com

• 8b21a945159f23b740c836eb50953818\.com

• 31d58c226fc5a0aa976e13ca9ecebcc8\.com

HexSDK

Download requests to files from the Hex SDK website redirect to castarsdk\.com. The SDKs are exactly the same.

EarnSDK

The EarnSDK JAR package for Android has strong overlaps with the other SDK brands analyzed. Earlier published samples contained the Tier One C2 domains:

• holadns\.com

• martianinc\.co

• okamiboss\.com

Of note, these domains were observed as part of the BadBox2.0 botnet and were sinkholed in our earlier litigation. Pivoting off these domains and other signatures, we identified some additional domains used as Tier One C2 domains: 

• v46wd6uramzkmeeo\.in

• 6b86b273ff34fce1\.online

• 0aa0cf0637d66c0d\.com

• aa86a52a98162b7d\.com

• 442fe7151fb1e9b5\.com

• BdRV7WlBszfOTkqF\.uk

Tier Two Nodes

Our analysis of various malware samples and the SDKs found a single shared pool of Tier Two servers. As of this writing there were approximately 7,400 Tier Two servers. The number of Tier Two nodes changes on a daily basis, consistent with a demand-based scaling system. They are hosted in locations around the globe, including the US. This indicates that despite different brand names and Tier One domains, the different SDKs in fact manage devices and proxy traffic through the same infrastructure.

Shared Sourcing of Exit Nodes

Trojanized Software Distribution

The IPIDEA actors also control domains that offer free Virtual Private Network services. While the applications do seem to provide VPN functionality, they also join the device to the IPIDEA proxy network as an exit node by incorporating Hex or Packet SDK. This is done without clear disclosures to the end user, nor is it the primary function of the application.

• Galleon VPN (galleonvpn\.com)

• Radish VPN (radishvpn\.com)

• Aman VPN (defunct)

Trojanized Windows Binaries

We identified a total of 3,075 unique Windows PE file hashes where dynamic analysis recorded a DNS request to at least one Tier One domain. A number of these hashes were for the monetized proxy exit node software, PacketShare. Our analysis also uncovered applications masquerading as OneDriveSync and Windows Update. These trojanized Windows applications were not distributed directly by the IPIDEA actors.

Android Application Analysis

We identified over 600 applications across multiple download sources with code connecting to Tier One C2 domains. These apps were largely benign in function (e.g., utilities, games, and content) but utilized monetization SDKs that enabled IPIDEA proxy behavior.

Our Actions

This week we took a number of steps designed to comprehensively dismantle as much of IPIDEA’s infrastructure as possible.

Protecting Devices

We took legal action to take down the C2 domains used by bad actors to control devices and proxy traffic. This protects consumer devices and home networks by disrupting the infrastructure at the source. 

To safeguard the Android ecosystem, we enforced our platform policies against trojanizing software, ensuring Google Play Protect on certified Android devices with Google Play services automatically warns users and removes applications known to incorporate IPIDEA software development kits (SDKs), and blocks any future install attempts.

Limiting IPIDEA’s Distribution

We took legal action to take down the domains used to market IPIDEA’s products, including proxy software and software development kits, across their various brands.

Coordinating with Industry Partners

We’ve shared our findings with industry partners to enable them to take action as well. We’ve worked closely with other firms, including Spur and Lumen’s Black Lotus Labs to understand the scope and extent of residential proxy networks and the bad behavior they often enable. We partnered with Cloudflare to disrupt IPIDEA’s domain resolution, impacting their ability to command and control infected devices and market their products. 

Call to Action

While we believe our actions have seriously impacted one of the largest residential proxy providers, this industry appears to be rapidly expanding, and there are significant overlaps across providers. As our investigation shows, the residential proxy market has become a "gray market" that thrives on deception—hijacking consumer bandwidth to provide cover for global espionage and cybercrime. More must be done to address the risks of these technologies. 

Empowering and Protecting the Consumer

Residential proxies are an understudied area of risk for consumers, and more can be done to raise awareness. Consumers should be extremely wary of applications that offer payment in exchange for "unused bandwidth" or "sharing your internet." These applications are primary ways for illicit proxy networks to grow, and could open security vulnerabilities on the device’s home network. We urge users to stick to official app stores, review permissions for third-party VPNs and proxies, and ensure built-in security protections like Google Play Protect are active.

Consumers should be careful when purchasing connected devices, such as set top boxes, to make sure they are from reputable manufacturers. For example, to help you confirm whether or not a device is built with the official Android TV OS and Play Protect certified, our Android TV website provides the most up-to-date list of partners. You can also take these steps to check if your Android device is Play Protect certified.

Proxy Accountability and Policy Reform

Residential proxy providers have been able to flourish under the guise of legitimate businesses. While some providers may indeed behave ethically and only enroll devices with the clear consent of consumers, any claims of "ethical sourcing" must be backed by transparent, auditable proof of user consent. Similarly, app developers have a responsibility to vet the monetization SDKs they integrate.

Industry Collaboration

We encourage mobile platforms, ISPs, and other tech platforms to continue sharing intelligence and implementing best practices to identify illicit proxy networks and limit their harms.

Indicators of Compromise (IOCs)

To assist the wider community in hunting and identifying activity outlined in this blog post, we have included a comprehensive list of indicators of compromise (IOCs) in a GTI Collection for registered users.

Network Indicators

File Indicators

Example Hashes

Introduction 

The Google Threat Intelligence Group (GTIG) has identified widespread, active exploitation of the critical vulnerability CVE-2025-8088 in WinRAR, a popular file archiver tool for Windows, to establish initial access and deliver diverse payloads. Discovered and patched in July 2025, government-backed threat actors linked to Russia and China as well as financially motivated threat actors continue to exploit this n-day across disparate operations. The consistent exploitation method, a path traversal flaw allowing files to be dropped into the Windows Startup folder for persistence, underscores a defensive gap in fundamental application security and user awareness.

In this blog post, we provide details on CVE-2025-8088 and the typical exploit chain, highlight exploitation by financially motivated and state-sponsored espionage actors, and provide IOCs to help defenders detect and hunt for the activity described in this post.

To protect against this threat, we urge organizations and users to keep software fully up-to-date and to install security updates as soon as they become available. After a vulnerability has been patched, malicious actors will continue to rely on n-days and use slow patching rates to their advantage. We also recommend the use of Google Safe Browsing and Gmail, which actively identifies and blocks files containing the exploit.

Vulnerability and Exploit Mechanism

CVE-2025-8088 is a high-severity path traversal vulnerability in WinRAR that attackers exploit by leveraging Alternate Data Streams (ADS). Adversaries can craft malicious RAR archives which, when opened by a vulnerable version of WinRAR, can write files to arbitrary locations on the system. Exploitation of this vulnerability in the wild began as early as July 18, 2025, and the vulnerability was addressed by RARLAB with the release of WinRAR version 7.13 shortly after, on July 30, 2025.

The exploit chain often involves concealing the malicious file within the ADS of a decoy file inside the archive. While the user typically views a decoy document (such as a PDF) within the archive, there are also malicious ADS entries, some containing a hidden payload while others are dummy data.

The payload is written with a specially crafted path designed to traverse to a critical directory, frequently targeting the Windows Startup folder for persistence. The key to the path traversal is the use of the ADS feature combined with directory traversal characters. 

For example, a file within the RAR archive might have a composite name like innocuous.pdf:malicious.lnk combined with a malicious path: ../../../../../Users/<user>/AppData/Roaming/Microsoft/Windows/Start Menu/Programs/Startup/malicious.lnk. 

When the archive is opened, the ADS content (malicious.lnk) is extracted to the destination specified by the traversal path, automatically executing the payload the next time the user logs in.

State-Sponsored Espionage Activity

Multiple government-backed actors have adopted the CVE-2025-8088 exploit, predominantly focusing on military, government, and technology targets. This is similar to the widespread exploitation of a known WinRAR bug in 2023, CVE-2023-38831, highlighting that exploits for known vulnerabilities can be highly effective, despite a patch being available.

Russia-Nexus Actors Targeting Ukraine

Suspected Russia-nexus threat groups are consistently exploiting CVE-2025-8088 in campaigns targeting Ukrainian military and government entities, using highly tailored geopolitical lures.

• UNC4895 (CIGAR): UNC4895 (also publicly reported as RomCom) is a dual financial and espionage-motivated threat group whose campaigns often involve spearphishing emails with lures tailored to the recipient. We observed subjects indicating targeting of Ukrainian military units. The final payload belongs to the NESTPACKER malware family (externally known as Snipbot).

• APT44 (FROZENBARENTS): This Russian APT group exploits CVE-2025-8088 to drop a decoy file with a Ukrainian filename, as well as a malicious LNK file that attempts further downloads.

• TEMP.Armageddon (CARPATHIAN): This actor, also targeting Ukrainian government entities, uses RAR archives to drop HTA files into the Startup folder. The HTA file acts as a downloader for a second stage. The initial downloader is typically contained within an archive packed inside an HTML file. This activity has continued through January 2026.

• Turla (SUMMIT): This actor adopted CVE-2025-8088 to deliver the STOCKSTAY malware suite. Observed lures are themed around Ukrainian military activities and drone operations.

China-Nexus Actors

• A PRC-based actor is exploiting the vulnerability to deliver POISONIVY malware via a BAT file dropped into the Startup folder, which then downloads a dropper.

Financially Motivated Activity

Financially motivated threat actors also quickly adopted the vulnerability to deploy commodity RATs and information stealers against commercial targets.

• A group that has targeted entities in Indonesia using lure documents used this vulnerability to drop a .cmd file into the Startup folder. This script then downloads a password-protected RAR archive from Dropbox, which contains a backdoor that communicates with a Telegram bot command and control.

• A group known for targeting the hospitality and travel sectors, particularly in LATAM, is using phishing emails themed around hotel bookings to eventually deliver commodity RATs such as XWorm and AsyncRAT.

• A group targeting Brazilian users via banking websites delivered a malicious Chrome extension that injects JavaScript into the pages of two Brazilian banking sites to display phishing content and steal credentials.

• In December and January 2026, we have continued to observe malware being distributed by cyber crime exploiting CVE-2025-8088, including commodity RATS and stealers. 

The Underground Exploit Ecosystem: Suppliers Like "zeroplayer"

The widespread use of CVE-2025-8088 by diverse actors highlights the demand for effective exploits. This demand is met by the underground economy where individuals and groups specialize in developing and selling exploits to a range of customers. A notable example of such an upstream supplier is the actor known as "zeroplayer," who advertised a WinRAR exploit in July 2025. 

The WinRAR vulnerability is not the only exploit in zeroplayer’s arsenal. Historically, and in recent months, zeroplayer has continued to offer other high-priced exploits that could potentially allow threat actors to bypass security measures. The actor’s advertised portfolio includes the following among others:

• In November 2025, zeroplayer claimed to have a sandbox escape RCE zero-day exploit for Microsoft Office advertising it for $300,000. 

• In late September 2025, zeroplayer advertised a RCE zero-day exploit for a popular, unnamed corporate VPN provider; the price for the exploit was not specified.

• Starting in mid-October 2025, zeroplayer advertised a zero-day Local Privilege Escalation (LPE) exploit for Windows listing its price as $100,000.

• In early September 2025, zeroplayer advertised a zero-day exploit for a vulnerability that exists in an unspecified drive that would allow an attacker to disable antivirus (AV) and endpoint detection and response (EDR) software; this exploit was advertised for $80,000.

zeroplayer’s continued activity as an upstream supplier of exploits highlights the continued commoditization of the attack lifecycle. By providing ready-to-use capabilities, actors such as zeroplayer reduce the technical complexity and resource demands for threat actors, allowing groups with diverse motivations—from ransomware deployment to state-sponsored intelligence gathering—to leverage a diverse set of capabilities.

Conclusion

The widespread and opportunistic exploitation of CVE-2025-8088 by a wide range of threat actors underscores its proven reliability as a commodity initial access vector. It also serves as a stark reminder of the enduring danger posed by n-day vulnerabilities. When a reliable proof of concept for a critical flaw enters the cyber criminal and espionage marketplace, adoption is instantaneous, blurring the line between sophisticated government-backed operations and financially motivated campaigns. This vulnerability’s rapid commoditization reinforces that a successful defense against these threats requires immediate application patching, coupled with a fundamental shift toward detecting the consistent, predictable post-exploitation TTPs.

Indicators of Compromise (IOCs)

To assist the wider community in hunting and identifying activity outlined in this blog post, we have included indicators of compromise (IOCs) in a GTI Collection for registered users.

File Indicators

The control panel for the Badbox 2.0 botnet lists seven authorized users and their email addresses. Click to enlarge.

A Google-translated version of Astrolink’s website, circa 2009. Image: archive.org.

The public information attached to Guilin Huang’s Microsoft account, according to the breach tracking service osintindustries.com.

This mind map includes search pivots on the email addresses, company names and phone numbers that appear to connect Chen Daihai and Zhu Zhiyu to Badbox 2.0. Click to enlarge.