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MITRE ATT&CK® Malware

S0538: Crutch

Crutch is a backdoor designed for document theft that has been used by Turla since at least 2015.[1]

EnterpriseS0538MalwareObject v1.0 Modified
Glexia's Take

Analyst context for executives and security teams

Analyst confidence Medium

Crutch matters because ATT&CK describes it as a Windows backdoor designed for document theft and associated with Turla use since at least 2015. For leaders, the practical issue is not just malware presence; it is whether the organization can notice document collection, local staging, archiving, and exfiltration over web, C2, or cloud-storage channels before sensitive data leaves the environment.

Executive priority

Prioritize Crutch as a data-theft and espionage readiness scenario: validate that high-value Windows systems, document repositories, removable media use, scheduled tasks, DLL activity, and outbound web/cloud traffic are covered by logging, monitoring, and response playbooks. This object is useful for testing whether SOC, incident response, compliance evidence, and data-loss controls can prove what documents were accessed, staged, archived, and transmitted.

Technical view

ATT&CK provides no official detection text for Crutch, so defenders should build validation from the related techniques: local and removable-media collection, peripheral discovery, automated collection and exfiltration, local staging, archive creation, scheduled task persistence, masqueraded tasks or services, DLL abuse, fallback C2, web-protocol C2, bidirectional web-service communication, exfiltration over C2, and exfiltration to cloud storage. Focus testing on Windows endpoints because that is the supplied platform for the malware object.

Likely telemetry

  • Windows endpoint process execution and command-line telemetry
  • Scheduled task creation, modification, and execution records
  • Windows service and task names, descriptions, paths, and signer metadata for masquerade review
  • DLL load events and file path metadata relevant to DLL abuse
  • File-system telemetry for document discovery, copying, staging directories, archive creation, and access to removable media

Detection direction

  • Because official detection guidance is not provided, validate behavior chains rather than a single malware signature.
  • Correlate document enumeration or bulk file access with local staging, archive utility use, and outbound transfer activity.
  • Review scheduled tasks and services for names that imitate legitimate administrative or system components, especially when paired with unusual executable paths.
  • Hunt for suspicious DLL loading patterns on Windows systems, particularly when followed by persistence or outbound communication.
  • Baseline normal cloud storage and web traffic so exfiltration to cloud services or C2 over web protocols does not disappear into routine business traffic.

Mitigation priorities

  • Start with visibility: ensure Windows endpoint, file, scheduled task, DLL, removable media, proxy/DNS, and cloud access telemetry is retained and searchable.
  • Restrict and monitor removable media and unsanctioned cloud storage use where business requirements allow.
  • Harden scheduled task and service creation permissions and regularly review persistence points on high-value systems.
  • Apply least privilege to sensitive document locations and monitor access to regulated or mission-critical data stores.
  • Use egress controls and proxy policy to limit unauthorized outbound channels while preserving business-approved web access.
Analyst notes and limits

The relationship set makes Crutch most useful as a collection-to-exfiltration scenario for control validation. The supplied ATT&CK relationship identifies Turla as a user of this malware, and the official description says Crutch has been used by Turla since at least 2015. Treat that as contextual intelligence; local evidence is still required for incident attribution.

ATT&CK does not provide official detection text, aliases, labels, or explicit tactics on the malware object. Technique relationships provide behavioral context, but they do not guarantee that every Crutch sample or intrusion will exhibit every behavior. Local baselines, approved administrative activity, cloud-service usage, and endpoint logging quality will determine practical detection value.

Official MITRE ATT&CK definition

Crutch

Crutch is a backdoor designed for document theft that has been used by Turla since at least 2015.[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.

15 rows
Domain ID Name Relationship / procedure
Enterprise T1560.001 Archive via Utility Sub-technique

Crutch has used the WinRAR utility to compress and encrypt stolen files.CitationESET Crutch December 2020

Enterprise T1120 Peripheral Device Discovery

Crutch can monitor for removable drives being plugged into the compromised machine.CitationESET Crutch December 2020

Enterprise T1102.002 Bidirectional Communication Sub-technique

Crutch can use Dropbox to receive commands and upload stolen data.CitationESET Crutch December 2020

Enterprise T1071.001 Web Protocols Sub-technique

Crutch has conducted C2 communications with a Dropbox account using the HTTP API.CitationESET Crutch December 2020

Enterprise T1053.005 Scheduled Task Sub-technique

Crutch has the ability to persist using scheduled tasks.CitationESET Crutch December 2020

Enterprise T1567.002 Exfiltration to Cloud Storage Sub-technique

Crutch has exfiltrated stolen data to Dropbox.CitationESET Crutch December 2020

Enterprise T1025 Data from Removable Media

Crutch can monitor removable drives and exfiltrate files matching a given extension list.CitationESET Crutch December 2020

Enterprise T1036.004 Masquerade Task or Service Sub-technique

Crutch has established persistence with a scheduled task impersonating the Outlook item finder.CitationESET Crutch December 2020

Enterprise T1574.001 DLL Sub-technique

Crutch can persist via DLL search order hijacking on Google Chrome, Mozilla Firefox, or Microsoft OneDrive.CitationESET Crutch December 2020

Enterprise T1020 Automated Exfiltration

Crutch has automatically exfiltrated stolen files to Dropbox.CitationESET Crutch December 2020

Enterprise T1119 Automated Collection

Crutch can automatically monitor removable drives in a loop and copy interesting files.CitationESET Crutch December 2020

Enterprise T1005 Data from Local System

Crutch can exfiltrate files from compromised systems.CitationESET Crutch December 2020

Enterprise T1008 Fallback Channels

Crutch has used a hardcoded GitHub repository as a fallback channel.CitationESET Crutch December 2020

Enterprise T1074.001 Local Data Staging Sub-technique

Crutch has staged stolen files in the C:\AMD\Temp directory.CitationESET Crutch December 2020

Enterprise T1041 Exfiltration Over C2 Channel

Crutch can exfiltrate data over the primary C2 channel (Dropbox HTTP API).CitationESET Crutch December 2020

Associated objects

Groups, software, and campaigns

Group Enterprise

G0010: Turla

Turla is a cyber espionage threat group that has been attributed to Russia's Federal Security Service (FSB). They have compromised victims in over 50 countries since at least 2004, spanning a range of industries including government, embassies, military, education, research and pharmaceutical companies. Turla is known for conducting watering hole and spearphishing campaigns, and leveraging in-house tools and malware, such as Uroburos.[1][2][3][4][5]

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
19.1
Object version
1.0
Created
Modified
Raw hash
78e8b456c888c451...
Imported snapshots across ATT&CK releases (1)
Release Bundle imported Object version Modified Status Raw hash
19.1 1.0 Current bundle 78e8b456c888…
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]
    ESET Crutch December 2020

    Faou, M. (2020, December 2). Turla Crutch: Keeping the “back door” open. Retrieved December 4, 2020.

    Open source URL
  2. [2]
    mitre-attack S0538
    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.