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Gamaredon

actor · actor:gamaredon

Russia-nexus (FSB-linked) APT focused on Ukrainian government targets; pipeline coverage documents the GammaPhish/GammaWorm NTFS-ADS USB+network worm (Sekoia) and ESET's 2025 annual paper on its tunnel/Workers/dead-drop infrastructure and collaboration with Turla.

Coverage
2
first 2026-06-02 → last 2026-08-30
Latest activity
2026-06-26
ESET's 2025 Gamaredon paper: exfil and C2 moved wholesale onto trusted cloud services (ANNUAL REPORT)
Peak priority
high
1 high · 1 notable
Targets
public-sector
sectors: public-sector, defense · regions: europe, russia-cis
Sources cited
5
5 hosts
2026-06-022 appearances2026-06-26

Action items (1)

Do-now tasks recorded on the entries about Gamaredon, newest first. Check the date before acting on an older one.

  • Inventory WinRAR to ≥ 7.13 and hunt Startup-folder writes to close the Gamaredon CVE-2025-8088 entry vector (§ 4); alert on archive utilities writing .exe/.vbs into Programs\Startup.
    2026-06-02CVE-2025-8088

Relationships explore in graph

Typed, source-stated connections from the entity registry; each edge cites the entry whose reporting establishes it.

collaborates with

Story timeline

  1. 2026-06-26ESET's 2025 Gamaredon paper: exfil and C2 moved wholesale onto trusted cloud services (ANNUAL REPORT)
    research
  2. 2026-06-02Sekoia consolidates Gamaredon tooling under GammaPhish / GammaWorm, details an NTFS-ADS USB+network worm
    research
ATT&CK techniques (8 across 7 tactics)

8 techniques observed across 1 entry about this entity, derived from entry metadata and body evidence, never asserted without a published entry behind it · pinned to MITRE ATT&CK v19.2 · compare on the matrix · Navigator layer (JSON)

  • Initial AccessReplication Through Removable Media
  • ExecutionScheduled Task/Job: Scheduled Task · Exploitation for Client Execution
  • PersistenceScheduled Task/Job: Scheduled Task · Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
  • Privilege EscalationScheduled Task/Job: Scheduled Task · Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
  • StealthObfuscated Files or Information · Hide Artifacts: NTFS File Attributes
  • Lateral MovementTaint Shared Content · Replication Through Removable Media
  • Command and ControlWeb Service: Dead Drop Resolver

Initial Access TA0001

T1091Replication Through Removable Media×1

Adversaries may move onto systems, possibly those on disconnected or air-gapped networks, by copying malware to removable media and taking advantage of Autorun features when the media is inserted into a system and executes. In the case of Lateral Movement, this may occur through modification of executable files stored on removable media or by copying malware and renaming it to look like a legitimate file to trick users into executing it on a separate system. In the case of Initial Access, this may occur through manual manipulation of the media, modification of systems used to initially format the media, or modification to the media's firmware itself.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

Execution TA0002

T1053.005Scheduled Task/Job: Scheduled Task×1

Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet `Invoke-CimMethod`, which leverages WMI class `PS_ScheduledTask` to create a scheduled task via an XML path.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

T1203Exploitation for Client Execution×1

Adversaries may exploit software vulnerabilities in client applications to execute code. Vulnerabilities can exist in software due to unsecure coding practices that can lead to unanticipated behavior. Adversaries can take advantage of certain vulnerabilities through targeted exploitation for the purpose of arbitrary code execution. Oftentimes the most valuable exploits to an offensive toolkit are those that can be used to obtain code execution on a remote system because they can be used to gain access to that system. Users will expect to see files related to the applications they commonly used to do work, so they are a useful target for exploit research and development because of their high utility.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

Persistence TA0003

T1053.005Scheduled Task/Job: Scheduled Task×1

Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet `Invoke-CimMethod`, which leverages WMI class `PS_ScheduledTask` to create a scheduled task via an XML path.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

T1547.001Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder×1

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

Privilege Escalation TA0004

T1053.005Scheduled Task/Job: Scheduled Task×1

Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet `Invoke-CimMethod`, which leverages WMI class `PS_ScheduledTask` to create a scheduled task via an XML path.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

T1547.001Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder×1

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

Stealth TA0005

T1027Obfuscated Files or Information×1

Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

T1564.004Hide Artifacts: NTFS File Attributes×1

Adversaries may use NTFS file attributes to hide their malicious data in order to evade detection. Every New Technology File System (NTFS) formatted partition contains a Master File Table (MFT) that maintains a record for every file/directory on the partition. Within MFT entries are file attributes, such as Extended Attributes (EA) and Data [known as Alternate Data Streams (ADSs) when more than one Data attribute is present], that can be used to store arbitrary data (and even complete files).

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

Lateral Movement TA0008

T1080Taint Shared Content×1

Adversaries may deliver payloads to remote systems by adding content to shared storage locations, such as network drives or internal code repositories. Content stored on network drives or in other shared locations may be tainted by adding malicious programs, scripts, or exploit code to otherwise valid files. Once a user opens the shared tainted content, the malicious portion can be executed to run the adversary's code on a remote system. Adversaries may use tainted shared content to move laterally.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

T1091Replication Through Removable Media×1

Adversaries may move onto systems, possibly those on disconnected or air-gapped networks, by copying malware to removable media and taking advantage of Autorun features when the media is inserted into a system and executes. In the case of Lateral Movement, this may occur through modification of executable files stored on removable media or by copying malware and renaming it to look like a legitimate file to trick users into executing it on a separate system. In the case of Initial Access, this may occur through manual manipulation of the media, modification of systems used to initially format the media, or modification to the media's firmware itself.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

Command and Control TA0011

T1102.001Web Service: Dead Drop Resolver×1

Adversaries may use an existing, legitimate external Web service to host information that points to additional command and control (C2) infrastructure. Adversaries may post content, known as a dead drop resolver, on Web services with embedded (and often obfuscated/encoded) domains or IP addresses. Once infected, victims will reach out to and be redirected by these resolvers.

Evidence: 2026-06-02/sekoia-consolidates-gamaredon-tooling-under-gammaphish-gamma · ATT&CK page ↗

Entries about Gamaredon (2)

2026-06-26 · view entry permalink →

HIGH

ESET's 2025 Gamaredon paper: exfil and C2 moved wholesale onto trusted cloud services (ANNUAL REPORT)

ESET's annual Gamaredon paper documents the FSB-linked group's 2025 toolset, six new PowerShell tools (PteroDee, PteroCache, PteroDum, PteroOdd, PteroEffigy, PteroPaste) plus a resurrected PteroSetup VBScript weaponizer, and, more usefully for defenders elsewhere, a wholesale shift of infrastructure onto trusted services (ESET, 2026-06-25). C2 now rides Cloudflare tunnels (trycloudflare.com), Cloudflare Workers (workers.dev), Microsoft DevTunnels (devtunnels.ms), Loophole, No-IP DDNS, Clever Cloud and Supabase; data is exfiltrated via rclone to S3-compatible object storage (Wasabi, Tebi, and Intercolo, which became the primary destination by December), and hostnames are brokered through dead-drop resolvers spread across Telegram, Telegra.ph, Dropbox, GoFile, Mastodon and a dozen paste services so no fixed IP or domain appears in the implant. ESET also confirms an early-2025 collaboration with Turla. Sekoia independently documented the same 2025 shift toward tunnel-service C2 and S3-compatible cloud-storage exfiltration in its parallel "FSB's Matryoshka" Gamaredon series (Sekoia, 2026-06-04). Targeting stayed exclusively Ukrainian government and military (the report names no EU targets) so the relevance here is the tradecraft, not the victimology.

Why it matters to us: the tunnel-and-cloud-storage model defeats domain/IP blocklists and blends with legitimate egress, and it is exactly the pattern any espionage operator can adopt. Detection concepts: alert on tunnel-service egress (trycloudflare.com / workers.dev / devtunnels.ms) initiated by Office or scripting processes; flag rclone or S3-API PUT/POST from hosts with no backup role; hunt PowerShell that reads paste-site domains and decodes base64 blobs.

annual-report26 Jun 04:54Zmulti-sourceOpen finding →

2026-06-02 · view entry permalink →

NOTABLECVE-2025-8088exploitedupdatedNATOB2

Sekoia consolidates Gamaredon tooling under GammaPhish / GammaWorm, details an NTFS-ADS USB+network worm

Sekoia's Threat Detection & Research team published part one of a Gamaredon (UAC-0010 / ACTINIUM, attributed to Russia's FSB) series describing a January 2026 campaign against Ukrainian government and military targets, introducing unified naming for two capability clusters: GammaPhish (the funnel from spearphishing through GammaLoad deployment) and GammaWorm (the propagation layer, subsuming the tooling previously tracked as LitterDrifter / PteroLNK) (Sekoia TDR, 2026-06-01 · Infosecurity Magazine, 2026-06-01). The chain begins with weaponised xHTML files exploiting CVE-2025-8088 (the WinRAR path-traversal flaw) to drop HTA payloads into Windows Startup directories via mshta.exe. GammaWorm itself is a 20,000+-line obfuscated VBScript worm that persists via scheduled tasks and RunOnce/Run registry keys, hides components in NTFS Alternate Data Streams, propagates across USB and mapped network drives using Ukrainian-language lures, and resolves C2 through dead-drop resolvers on Telegram, Telegra.ph, Teletype.in, Supabase and Cloudflare Workers.

Why it matters to us: The ADS-hiding + removable-media propagation + legitimate-service dead-drop pattern is highly transferable to any EU public-sector estate. Hunt for mshta.exe spawning wscript.exe, large obfuscated VBScripts executing from %APPDATA%, scheduled tasks with randomised GUID names pointing into user-profile paths, ADS on %TEMP%/%APPDATA% files, and outbound HTTPS to Telegra.ph / Supabase / Workers endpoints from non-developer hosts.

This archive exploits the CVE-2025-8088 vulnerability to extract a hidden HTA file directly into the user’s Windows Startup directory. Upon execution, the HTA file leverages mshta.exe to call a remote payload hosted on a C2 server.

Forensic analysis of compromised hosts revealed a highly obfuscated VBScript worm. It establishes persistence via scheduled tasks and actively conceals its core modules within NTFS Alternate Data Streams (ADS).

Sekoia TDR
Updaterun 2026-06-03-ee0eae61actionscvesevidenceregionssourcestagsbody

Sekoia TDR's "FSB's Matryoshka" series adds material technical detail to the Gamaredon (UAC-0010 / ACTINIUM) tooling consolidation covered yesterday: the group is exploiting the WinRAR path-traversal flaw CVE-2025-8088 as an initial-access vector, using the traversal to write payloads directly into %APPDATA%\…\Start Menu\Programs\Startup\ for persistence without a Registry or Scheduled-Task artefact (Sekoia TDR, 2026-06-01).

The series also names GammaSteel, a modular file-stealer (consolidating prior QuietSieve/HarvesterX-class modules) that captures files by extension and (newly) exfiltrates to attacker-controlled S3-compatible cloud storage in addition to Gamaredon's previously documented HTTP/Telegram channels (The Hacker News, 2026-06-02). The full chain runs WinRAR archive → GammaPhish (HTA) → GammaLoad (VBScript downloader) → GammaWorm/GammaSteel.

Delta for defenders: CVE-2025-8088 is fixed in WinRAR 7.13 (August 2025), so the entry vector is closed by patching, inventory WinRAR versions across the estate. Hunt for archive utilities writing executables or .vbs into Programs\Startup paths (Sysmon EID 11 on target path containing Programs\Startup), WinRAR spawning wscript.exe/mshta.exe, and VBScript processes making outbound requests to S3 endpoints inconsistent with normal business traffic. The targeting is Ukraine-centric, but the WinRAR vector reaches any organisation that opens archive-format lures.

Improvementrun 2026-08-30T1312Z-auditactionsclassificationtechniquesevidence

Three things on this entry are now right that were not.

It carries a source-reliability rating it predated: B2. Sekoia TDR is an original research lab, and the two outlets alongside it republish that report rather than assessing the campaign independently, so corroboration does not lift the credibility number.

Its cited evidence was wrong. The single evidence record reproduced an earlier summary of this entry's own update and attributed it to a publisher that never wrote it. It is replaced with two passages quoted directly from Sekoia's report: "This archive exploits the CVE-2025-8088 vulnerability to extract a hidden HTA file directly into the user's Windows Startup directory. Upon execution, the HTA file leverages mshta.exe to call a remote payload hosted on a C2 server", and "Forensic analysis of compromised hosts revealed a highly obfuscated VBScript worm. It establishes persistence via scheduled tasks and actively conceals its core modules within NTFS Alternate Data Streams (ADS)" (Sekoia TDR, 2026-06-01).

Its ATT&CK mapping was empty despite a body describing a full chain, so nothing in this entry reached the technique matrix or the actor profile. It now maps the WinRAR exploitation, the Startup-folder and scheduled-task persistence, the Alternate Data Stream concealment, the dead-drop resolvers on legitimate web services (the exact sub-technique, not the parent web-service class), the tainting of USB and network-drive content, and the script obfuscation. No claim in the analysis changed.

research02 Jun 05:00Zmulti-sourceOpen finding →

Co-occurring entities

Derived: referenced by the same focused operational entries (weekly summaries and report roundups don't count); ×N counts the shared entries.

Where this entity is cited

  • Research2

Source distribution

  • blog.sekoia.io1 (20%)
  • infosecurity-magazine.com1 (20%)
  • sekoia.com1 (20%)
  • thehackernews.com1 (20%)
  • welivesecurity.com1 (20%)