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MITRE ATT&CK® Malware

S1011: Tarrask

Tarrask is malware that has been used by HAFNIUM since at least August 2021. Tarrask was designed to evade digital defenses and maintain persistence by generating concealed scheduled tasks.[1]

EnterpriseS1011MalwareObject v1.0Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

S1011: Tarrask describes [Tarrask](https://attack.mitre.org/software/S1011) is malware that has been used by [HAFNIUM](https://attack.mitre.org/groups/G0125) since at least August 2021. [Tarrask](https://attack.mitre.org/software/S1011) was designed to evade digital defenses and maintain persistence by generating concealed scheduled tasks.(Citation: Tarrask scheduled task)

Executive priority

S1011: Tarrask is an official MITRE ATT&CK software. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.

Technical view

Security teams should validate S1011: Tarrask by reviewing the official ATT&CK relationships, mapped tactics (the mapped ATT&CK tactic context), supported platforms (Windows), and available local telemetry before making detection or mitigation decisions.

Likely telemetry

  • Official ATT&CK relationships and object metadata
  • Network, endpoint, and security-tool telemetry

Detection direction

  • Validate whether S1011: Tarrask appears in your detection coverage and tabletop scenarios.
  • Use the object to align executive risk language with SOC, incident response, and detection engineering work.
  • Do not treat ATT&CK relationship context as attribution without corroborating evidence.

Mitigation priorities

  • Map the object to existing controls and identify missing telemetry or response ownership.
  • Prioritize mitigations that reduce exposure on the listed platforms and tactics.
  • Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.
Additional notes and limits

Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.

This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Official MITRE ATT&CK definition

Tarrask

Tarrask is malware that has been used by HAFNIUM since at least August 2021. Tarrask was designed to evade digital defenses and maintain persistence by generating concealed scheduled tasks.[1]

View the same entry on attack.mitre.org (MITRE-hosted reference; in-page links above use the Glexia ATT&CK library.)

Glexia analysis

How security teams should use this page

Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.

ATT&CK relationship table

Techniques used

This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.

7 rows
DomainIDNameRelationship / procedure
EnterpriseT1036.005Match Legitimate Resource Name or LocationSub-technique

Tarrask has masqueraded as executable files such as `winupdate.exe`, `date.exe`, or `win.exe`.[1]

EnterpriseT1059.003Windows Command ShellSub-technique

Tarrask may abuse the Windows schtasks command-line tool to create "hidden" scheduled tasks.[1]

EnterpriseT1134.001Token Impersonation/TheftSub-technique

Tarrask leverages token theft to obtain `lsass.exe` security permissions.[1]

EnterpriseT1036.004Masquerade Task or ServiceSub-technique

Tarrask creates a scheduled task called “WinUpdate” to re-establish any dropped C2 connections.[1]

EnterpriseT1053.005Scheduled TaskSub-technique

Tarrask is able to create “hidden” scheduled tasks for persistence.[1]

EnterpriseT1112Modify Registry

Tarrask is able to delete the Security Descriptor (`SD`) registry subkey in order to “hide” scheduled tasks.[1]

EnterpriseT1564Hide Artifacts

Tarrask is able to create “hidden” scheduled tasks by deleting the Security Descriptor (`SD`) registry value.[1]

Associated objects

Groups, software, and campaigns

GroupEnterprise

G0125: HAFNIUM

HAFNIUM is a likely state-sponsored cyber espionage group operating out of China that has been active since at least January 2021. HAFNIUM primarily targets entities in the US across a number of industry sectors, including infectious disease researchers, law firms, higher education institutions, defense contractors, policy think tanks, and NGOs. HAFNIUM has targeted remote management tools and cloud software for intial access and has demonstrated an ability to quickly operationalize exploits for identified vulnerabilities in edge devices.[1][2][3]

Relationship explorer

All related ATT&CK context

Change history

Object version and sync metadata

The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.

ATT&CK release
19.2
Object version
1.0
Created
Modified
Raw hash
0365bf8b1c3d54ab...
Imported snapshots across ATT&CK releases(2)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.21.0Current bundle0365bf8b1c3d…
19.11.0Older bundle0365bf8b1c3d…
Raw source

Mirrored ATT&CK source object

The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.

Source references

External references and citations

MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.

  1. [1]
    Tarrask scheduled task

    Microsoft Threat Intelligence Team & Detection and Response Team . (2022, April 12). Tarrask malware uses scheduled tasks for defense evasion. Retrieved June 1, 2022.

    Open source URL
  2. [2]
    mitre-attackS1011
    Open source URL
Source and licensing

Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.