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MITRE ATT&CK® Group

G0003: Cleaver

Cleaver is a threat group that has been attributed to Iranian actors and is responsible for activity tracked as Operation Cleaver. [1] Strong circumstantial evidence suggests Cleaver is linked to Threat Group 2889 (TG-2889). [2]

EnterpriseG0003GroupObject v1.3 Modified
Glexia's Take

Analyst context for executives and security teams

Analyst confidence Medium

Cleaver is an ATT&CK group entry associated in MITRE reporting with Iranian actors and Operation Cleaver, with circumstantial linkage to Threat Group 2889/TG-2889. The useful defensive takeaway is not the name alone: the related ATT&CK relationships point to credential theft, Windows administrative tooling, SMB-based spreading, malware development, and social-media persona development as areas leaders should expect defenders to validate.

Executive priority

Prioritize assurance around identity security and Windows lateral-movement readiness. The relationships to Mimikatz, LSASS memory access, PsExec, and Net Crawler make credential exposure and administrator-tool abuse the main business concerns. Executives should ask whether the organization can prove it collects the logs needed to investigate credential dumping, remote execution, SMB propagation, and suspicious social-engineering preparation, rather than relying on group attribution as the control driver.

Technical view

SOC and IR teams should map coverage around the related behaviors: LSASS credential access on Windows, use or misuse of PsExec, SMB-based movement or brute-force propagation associated with Net Crawler behavior, ARP cache poisoning on local networks, and pre-compromise resource development such as social media personas, malware, and tool acquisition. Because the ATT&CK object has no official detection text and no platforms listed for the group itself, validation should be behavior-led and tied to the related software and techniques rather than the Cleaver name.

Likely telemetry

  • Windows endpoint telemetry for process creation, parent-child process relationships, service creation, and command execution
  • Security event logs and authentication telemetry for privileged logons, failed logons, and lateral authentication patterns
  • Endpoint detections or memory-access telemetry involving LSASS access
  • SMB and remote administration activity, including PsExec-like remote service execution
  • Network telemetry for unusual ARP behavior or local man-in-the-middle indicators where available

Detection direction

  • Validate behavior-based detections for credential dumping and suspicious access to LSASS rather than relying on static tool names alone.
  • Tune PsExec detections carefully because it is also a legitimate Microsoft administrative tool; combine execution telemetry with user, host, timing, and change-management context.
  • Hunt for SMB propagation patterns, repeated authentication attempts, and remote execution chains consistent with worm-like movement described for Net Crawler.
  • Assess whether network monitoring can observe ARP cache poisoning in relevant segments; many environments have limited east-west Layer 2 visibility.
  • Use the resource-development relationships as threat-intelligence context for social engineering readiness, not as proof of compromise inside the environment.

Mitigation priorities

  • Strengthen privileged access management and reduce standing administrative privileges on Windows systems.
  • Harden credential protections around LSASS and validate that endpoint controls alert on suspicious credential access attempts.
  • Restrict and monitor remote administration pathways such as PsExec-style service execution and SMB where business requirements allow.
  • Apply network segmentation to reduce the blast radius of SMB-based lateral movement.
  • Improve account lockout, password hygiene, and monitoring for brute-force or recovered-password use across internal systems.
Analyst notes and limits

This take is based on the supplied ATT&CK group description, aliases, references, and explicit relationships. The group object itself does not list platforms, tactics, or official detection guidance; the Windows and PRE context comes from related software and techniques. Attribution should be treated as MITRE-reported context, not as a basis for assuming current targeting or exposure.

The supplied object does not provide procedure-level details, indicators, timestamps of activity, sector targeting, impact claims, or official detections. Local telemetry, asset criticality, identity architecture, and approved administrative-tool usage are required to determine real coverage and risk.

Official MITRE ATT&CK definition

Cleaver

Cleaver is a threat group that has been attributed to Iranian actors and is responsible for activity tracked as Operation Cleaver. [1] Strong circumstantial evidence suggests Cleaver is linked to Threat Group 2889 (TG-2889). [2]

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.

5 rows
Domain ID Name Relationship / procedure
Enterprise T1003.001 LSASS Memory Sub-technique

Cleaver has been known to dump credentials using Mimikatz and Windows Credential Editor.CitationCylance Cleaver

Enterprise T1557.002 ARP Cache Poisoning Sub-technique

Cleaver has used custom tools to facilitate ARP cache poisoning.CitationCylance Cleaver

Enterprise T1588.002 Tool Sub-technique

Cleaver has obtained and used open-source tools such as PsExec, Windows Credential Editor, and Mimikatz.CitationCylance Cleaver

Enterprise T1587.001 Malware Sub-technique

Cleaver has created customized tools and payloads for functions including ARP poisoning, encryption, credential dumping, ASP.NET shells, web backdoors, process enumeration, WMI querying, HTTP and SMB communications, network interface sniffing, and keystroke logging.CitationCylance Cleaver

Enterprise T1585.001 Social Media Accounts Sub-technique

Cleaver has created fake LinkedIn profiles that included profile photos, details, and connections.CitationDell Threat Group 2889

Associated objects

Groups, software, and campaigns

Malware Enterprise

S0056: Net Crawler

Net Crawler is an intranet worm capable of extracting credentials using credential dumpers and spreading to systems on a network over SMB by brute forcing accounts with recovered passwords and using PsExec to execute a copy of Net Crawler. [1]

Windows
Tool Enterprise

S0029: PsExec

PsExec is a free Microsoft tool that can be used to execute a program on another computer. It is used by IT administrators and attackers.[1][2]

Windows
Tool Enterprise

S0002: Mimikatz

Mimikatz is a credential dumper capable of obtaining plaintext Windows account logins and passwords, along with many other features that make it useful for testing the security of networks. [1] [2]

Windows
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
1.3
Created
Modified
Raw hash
25c436a3436d6ce8...
Imported snapshots across ATT&CK releases (1)
Release Bundle imported Object version Modified Status Raw hash
19.1 1.3 Current bundle 25c436a3436d…
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]
    Cylance Cleaver

    Cylance. (2014, December). Operation Cleaver. Retrieved September 14, 2017.

    Open source URL
  2. [2]
    Dell Threat Group 2889

    Dell SecureWorks. (2015, October 7). Suspected Iran-Based Hacker Group Creates Network of Fake LinkedIn Profiles. Retrieved January 14, 2016.

    Open source URL
  3. [3]
    Cleaver

    (Citation: Cylance Cleaver)

  4. [4]
    TG-2889

    (Citation: Dell Threat Group 2889)

  5. [5]
    Threat Group 2889

    (Citation: Dell Threat Group 2889)

  6. [6]
    mitre-attack G0003
    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.