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MITRE ATT&CK® Malware

S0514: WellMess

WellMess is lightweight malware family with variants written in .NET and Golang that has been in use since at least 2018 by APT29.[1][2][3]

EnterpriseS0514MalwareObject v1.0Modified
Glexia's Take · Automated analysis

Security context for executives and security teams

Automation confidenceMedium

S0514: WellMess describes [WellMess](https://attack.mitre.org/software/S0514) is lightweight malware family with variants written in .NET and Golang that has been in use since at least 2018 by [APT29](https://attack.mitre.org/groups/G0016).(Citation: CISA WellMess July 2020)(Citation: PWC WellMess July 2020)(Citation: NCSC APT29 July 2020)

Executive priority

S0514: WellMess 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 S0514: WellMess 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 S0514: WellMess 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

WellMess

WellMess is lightweight malware family with variants written in .NET and Golang that has been in use since at least 2018 by APT29.[1][2][3]

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
DomainIDNameRelationship / procedure
EnterpriseT1033System Owner/User Discovery

WellMess can collect the username on the victim machine to send to C2.[1]

EnterpriseT1059.001PowerShellSub-technique

WellMess can execute PowerShell scripts received from C2.[2][1]

EnterpriseT1005Data from Local System

WellMess can send files from the victim machine to C2.[2][1]

EnterpriseT1071.004DNSSub-technique

WellMess has the ability to use DNS tunneling for C2 communications.[2][3]

EnterpriseT1082System Information Discovery

WellMess can identify the computer name of a compromised host.[2][1]

EnterpriseT1105Ingress Tool Transfer

WellMess can write files to a compromised host.[2][1]

EnterpriseT1573.002Asymmetric CryptographySub-technique

WellMess can communicate to C2 with mutual TLS where client and server mutually check certificates.[2]CitationPWC WellMess C2 August 2020[1][3]

EnterpriseT1132.001Standard EncodingSub-technique

WellMess has used Base64 encoding to uniquely identify communication to and from the C2.[1]

EnterpriseT1573.001Symmetric CryptographySub-technique

WellMess can encrypt HTTP POST data using RC6 and a dynamically generated AES key encrypted with a hard coded RSA public key.[2]CitationPWC WellMess C2 August 2020[1]

EnterpriseT1059.003Windows Command ShellSub-technique

WellMess can execute command line scripts received from C2.[2]

EnterpriseT1069.002Domain GroupsSub-technique

WellMess can identify domain group membership for the current user.[1]

EnterpriseT1016System Network Configuration Discovery

WellMess can identify the IP address and user domain on the target machine.[2][1]

EnterpriseT1140Deobfuscate/Decode Files or Information

WellMess can decode and decrypt data received from C2.[2]CitationPWC WellMess C2 August 2020[1]

EnterpriseT1071.001Web ProtocolsSub-technique

WellMess can use HTTP and HTTPS in C2 communications.[2]CitationPWC WellMess C2 August 2020[1][3]

EnterpriseT1001.001Junk DataSub-technique

WellMess can use junk data in the Base64 string for additional obfuscation.[1]

Associated objects

Groups, software, and campaigns

GroupEnterprise

G0016: APT29

APT29 is threat group that has been attributed to Russia's Foreign Intelligence Service (SVR).[1][2] They have operated since at least 2008, often targeting government networks in Europe and NATO member countries, research institutes, and think tanks. APT29 reportedly compromised the Democratic National Committee starting in the summer of 2015.[3][4][5][6]

In April 2021, the US and UK governments attributed the SolarWinds Compromise to the SVR; public statements included citations to APT29, Cozy Bear, and The Dukes.[7][8] Industry reporting also referred to the actors involved in this campaign as UNC2452, NOBELIUM, StellarParticle, Dark Halo, and SolarStorm.[9][10][11][12][13][14]

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
029d3c7d48717412...
Imported snapshots across ATT&CK releases(2)
ReleaseBundle importedObject versionModifiedStatusRaw hash
19.21.0Current bundle029d3c7d4871…
19.11.0Older bundle029d3c7d4871…
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]
    CISA WellMess July 2020

    CISA. (2020, July 16). MAR-10296782-2.v1 – WELLMESS. Retrieved September 24, 2020.

    Open source URL
  2. [2]
    PWC WellMess July 2020

    PWC. (2020, July 16). How WellMess malware has been used to target COVID-19 vaccines. Retrieved September 24, 2020.

    Open source URL
  3. [3]
    NCSC APT29 July 2020

    National Cyber Security Centre. (2020, July 16). Advisory: APT29 targets COVID-19 vaccine development. Retrieved September 29, 2020.

    Open source URL
  4. [4]
    mitre-attackS0514
    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.