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MITRE ATT&CK® Group

G0127: TA551

TA551 is a financially-motivated threat group that has been active since at least 2018. [1] The group has primarily targeted English, German, Italian, and Japanese speakers through email-based malware distribution campaigns. [2]

EnterpriseG0127GroupObject v1.2Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

TA551 is a financially motivated ATT&CK group associated with email-based malware distribution campaigns aimed at English, German, Italian, and Japanese speakers. For leaders, the practical issue is not just “phishing”: the relationships show a pattern that can involve malicious attachments, user execution, Windows living-off-the-land utilities, obfuscation, web-based command and control, tool transfer, and malware families such as Ursnif, Valak, IcedID, QakBot, and Sliver. This makes email security, endpoint visibility, and incident response readiness the key decision areas.

Executive priority

Prioritize TA551 as an email-led intrusion risk that can affect business continuity through credential or financial data theft, malware deployment, and follow-on access. Executives should ask whether the organization can prove coverage across the full chain: exposed email-address collection, malicious attachment delivery, user execution, suspicious Windows utility use, outbound web C2, DGA-like DNS behavior, and downloaded tooling. This is also useful for audit and compliance evidence because it tests whether phishing defenses, endpoint logging, network monitoring, and response playbooks operate together rather than as isolated controls.

Technical view

ATT&CK does not provide a dedicated detection section for TA551, so validation should be built from the related techniques and software. SOC and detection teams should map coverage for T1566.001 Spearphishing Attachment, T1204.002 Malicious File, T1059.003 Windows Command Shell, T1218.005 Mshta, T1218.010 Regsvr32, T1218.011 Rundll32, T1027.003 Steganography, T1027.010 Command Obfuscation, T1071.001 Web Protocols, T1105 Ingress Tool Transfer, T1132.001 Standard Encoding, T1568.002 Domain Generation Algorithms, and T1589.002 Email Addresses. Because several related malware entries list Windows and Sliver is cross-platform, endpoint and network validation should not rely on email gateway alerts alone.

Likely telemetry

  • Email gateway and mailbox telemetry for attachments, sender metadata, URLs, and user reporting outcomes
  • Endpoint process creation telemetry for cmd.exe, mshta.exe, regsvr32.exe, rundll32.exe, script interpreters, and parent-child process chains from email clients or document readers
  • File creation and execution telemetry for downloaded or attachment-originated files, including archives, documents, scripts, DLLs, and executables
  • DNS logs for high-volume, algorithmic, newly observed, or unusual domain lookups consistent with DGA-style behavior
  • Web proxy, firewall, and TLS metadata for outbound HTTP/S or WebSocket-like command-and-control patterns

Detection direction

  • Validate correlation from email delivery to endpoint execution; isolated phishing detections may miss post-click activity.
  • Tune detections for suspicious use of mshta.exe, regsvr32.exe, rundll32.exe, and cmd.exe, especially when launched from office productivity tools, email clients, temporary directories, or user-writable paths.
  • Hunt for command obfuscation and standard encodings such as Base64 or hexadecimal in command lines and script content, while accounting for legitimate administrative scripts.
  • Review network detections for outbound web protocols used by unusual processes, rare destinations, or newly observed domains; avoid relying only on static domain blocklists because DGA-related behavior is listed.
  • Include malware-family context for Ursnif, Valak, IcedID, QakBot, and Sliver in threat intelligence enrichment, but confirm local indicators before treating an alert as TA551-related.

Mitigation priorities

  • Reduce initial access risk first: strengthen email attachment controls, sandboxing, user reporting workflows, and handling of high-risk attachment types.
  • Harden execution paths: restrict or monitor abuse-prone Windows utilities such as mshta.exe, regsvr32.exe, and rundll32.exe where business use is limited.
  • Improve endpoint visibility and response: ensure process, command-line, file, and network telemetry are retained long enough to reconstruct email-to-execution events.
  • Strengthen outbound controls: monitor and filter suspicious web traffic, unusual DNS behavior, and external payload downloads.
  • Use threat intelligence operationally: map detections and playbooks to the related malware and techniques, but avoid assuming attribution without corroborating evidence.
Additional notes and limits

The supplied ATT&CK object identifies TA551 as financially motivated, active since at least 2018, and primarily associated with email-based malware distribution campaigns targeting speakers of specific languages. The strongest defensive value comes from the relationship set, which connects the group to phishing attachments, malicious file execution, Windows proxy execution utilities, obfuscation, web C2, DGA behavior, and several malware families or frameworks.

ATT&CK provides no official detection text for this group, and the group object itself lists no platforms or tactics. Platform references here come only from related software and techniques. Local telemetry, business process knowledge, and current threat intelligence are required before asserting exposure, detection coverage, incident attribution, or active targeting.

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

Official MITRE ATT&CK definition

TA551

TA551 is a financially-motivated threat group that has been active since at least 2018. [1] The group has primarily targeted English, German, Italian, and Japanese speakers through email-based malware distribution campaigns. [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.

14 rows
DomainIDNameRelationship / procedure
EnterpriseT1218.010Regsvr32Sub-technique

TA551 has used regsvr32.exe to load malicious DLLs.[3]

EnterpriseT1589.002Email AddressesSub-technique

TA551 has used spoofed company emails that were acquired from email clients on previously infected hosts to target other individuals.[2]

EnterpriseT1204.002Malicious FileSub-technique

TA551 has prompted users to enable macros within spearphishing attachments to install malware.[2]

EnterpriseT1218.011Rundll32Sub-technique

TA551 has used rundll32.exe to load malicious DLLs.[2]

EnterpriseT1027.003SteganographySub-technique

TA551 has hidden encoded data for malware DLLs in a PNG.[2]

EnterpriseT1566.001Spearphishing AttachmentSub-technique

TA551 has sent spearphishing attachments with password protected ZIP files.[3][2][1]

EnterpriseT1132.001Standard EncodingSub-technique

TA551 has used encoded ASCII text for initial C2 communications.[3]

EnterpriseT1568.002Domain Generation AlgorithmsSub-technique

TA551 has used a DGA to generate URLs from executed macros.[2][1]

EnterpriseT1027.010Command ObfuscationSub-technique

TA551 has used obfuscated variable names in a JavaScript configuration file.[3]

EnterpriseT1071.001Web ProtocolsSub-technique

TA551 has used HTTP for C2 communications.[3]

EnterpriseT1105Ingress Tool Transfer

TA551 has retrieved DLLs and installer binaries for malware execution from C2.[2]

EnterpriseT1218.005MshtaSub-technique

TA551 has used mshta.exe to execute malicious payloads.[2]

EnterpriseT1059.003Windows Command ShellSub-technique

TA551 has used cmd.exe to execute commands.[2]

EnterpriseT1036Masquerading

TA551 has masked malware DLLs as dat and jpg files.[2]

Associated objects

Groups, software, and campaigns

MalwareEnterprise

S0650: QakBot

QakBot is a modular banking trojan that has been used primarily by financially-motivated actors since at least 2007. QakBot is continuously maintained and developed and has evolved from an information stealer into a delivery agent for ransomware, most notably ProLock and Egregor.[1][2][3][4]

Windows
MalwareEnterprise

S0483: IcedID

IcedID is a modular banking malware designed to steal financial information that has been observed in the wild since at least 2017. IcedID has been downloaded by Emotet in multiple campaigns.[1][2]

Windows
MalwareEnterprise

S0476: Valak

Valak is a multi-stage modular malware that can function as a standalone information stealer or downloader, first observed in 2019 targeting enterprises in the US and Germany.[1][2]

Windows
ToolEnterprise

S0633: Sliver

Sliver is an open source, cross-platform, red team command and control (C2) framework written in Golang. Sliver includes its own package manager, "armory," for staging and downloading additional tools and payloads to the primary C2 framework.[1][2]

WindowsLinuxmacOS
MalwareEnterprise

S0386: Ursnif

Ursnif is a banking trojan and variant of the Gozi malware observed being spread through various automated exploit kits, Spearphishing Attachments, and malicious links.[1][2] Ursnif is associated primarily with data theft, but variants also include components (backdoors, spyware, file injectors, etc.) capable of a wide variety of behaviors.[3]

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
1.2
Created
Modified
Raw hash
2801977a311554d8...
Imported snapshots across ATT&CK releases(1)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.11.2Current bundle2801977a3115…
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]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  2. [2]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  3. [3]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  4. [4]
    ATT QakBot April 2021

    Morrow, D. (2021, April 15). The rise of QakBot. Retrieved September 27, 2021.

    Open source URL
  5. [5]
    Cybereason Valak May 2020

    Salem, E. et al. (2020, May 28). VALAK: MORE THAN MEETS THE EYE . Retrieved June 19, 2020.

    Open source URL
  6. [6]
    Cybereason Sliver Undated

    Cybereason Global SOC and Incident Response Team. (n.d.). Sliver C2 Leveraged by Many Threat Actors. Retrieved March 24, 2025.

    Open source URL
  7. [7]
    GOLD CABIN

    (Citation: Secureworks GOLD CABIN)

  8. [8]
    GOLD CABIN

    (Citation: Secureworks GOLD CABIN)

  9. [9]
    GOLD CABIN

    (Citation: Secureworks GOLD CABIN)

  10. [10]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  11. [11]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  12. [12]
    Shathak

    (Citation: Unit 42 Valak July 2020)(Citation: Unit 42 TA551 Jan 2021)

  13. [13]
    Shathak

    (Citation: Unit 42 Valak July 2020)(Citation: Unit 42 TA551 Jan 2021)

  14. [14]
    Shathak

    (Citation: Unit 42 Valak July 2020)(Citation: Unit 42 TA551 Jan 2021)

  15. [15]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  16. [16]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  17. [17]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  18. [18]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
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    mitre-attackG0127
    Open source URL
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    mitre-attackG0127
    Open source URL
  21. [21]
    mitre-attackG0127
    Open source URL
  22. [22]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  23. [23]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  24. [24]
    ATT QakBot April 2021

    Morrow, D. (2021, April 15). The rise of QakBot. Retrieved September 27, 2021.

    Open source URL
  25. [25]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  26. [26]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  27. [27]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  28. [28]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  29. [29]
    Cybereason Valak May 2020

    Salem, E. et al. (2020, May 28). VALAK: MORE THAN MEETS THE EYE . Retrieved June 19, 2020.

    Open source URL
  30. [30]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  31. [31]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  32. [32]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  33. [33]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  34. [34]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  35. [35]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  36. [36]
    Cybereason Valak May 2020

    Salem, E. et al. (2020, May 28). VALAK: MORE THAN MEETS THE EYE . Retrieved June 19, 2020.

    Open source URL
  37. [37]
    Cybereason Valak May 2020

    Salem, E. et al. (2020, May 28). VALAK: MORE THAN MEETS THE EYE . Retrieved June 19, 2020.

    Open source URL
  38. [38]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  39. [39]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  40. [40]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  41. [41]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  42. [42]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  43. [43]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  44. [44]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  45. [45]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  46. [46]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  47. [47]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
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    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
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    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  50. [50]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  51. [51]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  52. [52]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  53. [53]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  54. [54]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  55. [55]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  56. [56]
    Cybereason Sliver Undated

    Cybereason Global SOC and Incident Response Team. (n.d.). Sliver C2 Leveraged by Many Threat Actors. Retrieved March 24, 2025.

    Open source URL
  57. [57]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
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    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
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    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
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    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
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    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
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    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
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    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
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    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
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    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
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    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
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    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  68. [68]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  69. [69]
    Cybereason Valak May 2020

    Salem, E. et al. (2020, May 28). VALAK: MORE THAN MEETS THE EYE . Retrieved June 19, 2020.

    Open source URL
  70. [70]
    Secureworks GOLD CABIN

    Secureworks. (n.d.). GOLD CABIN Threat Profile. Retrieved March 17, 2021.

    Open source URL
  71. [71]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    Open source URL
  72. [72]
    Unit 42 Valak July 2020

    Duncan, B. (2020, July 24). Evolution of Valak, from Its Beginnings to Mass Distribution. Retrieved August 31, 2020.

    Open source URL
  73. [73]
    Unit 42 TA551 Jan 2021

    Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.

    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.