T1218.009: Regsvcs/Regasm
Adversaries may abuse Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies. Both are binaries that may be digitally signed by Microsoft. [1] [2]
Both utilities may be used to bypass application control through use of attributes within the binary to specify code that should be run before registration or unregistration: [ComRegisterFunction] or [ComUnregisterFunction] respectively. The code with the registration and unregistration attributes will be executed even if the process is run under insufficient privileges and fails to execute. [3][4]
Security context for executives and security teams
T1218.009: Regsvcs/Regasm describes Adversaries may abuse Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Regsvcs and Regasm are Windows command-line utilities that are used to register .NET [Component Object Model](https://attack.mitre.org/techniques/T1559/001) (COM) assemblies. Both are binaries that may be digitally signed by Microsoft. (Citation: MSDN Regsvcs) (Citation: MSDN Regasm) Both utilities may be used to bypass application control through use of attributes within the binary to specify code that should be ...
Executive priority
T1218.009: Regsvcs/Regasm is an official MITRE ATT&CK technique. 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 T1218.009: Regsvcs/Regasm by reviewing the official ATT&CK relationships, mapped tactics (stealth), 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 T1218.009: Regsvcs/Regasm 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.
Regsvcs/Regasm
Adversaries may abuse Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies. Both are binaries that may be digitally signed by Microsoft. [1] [2]
Both utilities may be used to bypass application control through use of attributes within the binary to specify code that should be run before registration or unregistration: [ComRegisterFunction] or [ComUnregisterFunction] respectively. The code with the registration and unregistration attributes will be executed even if the process is run under insufficient privileges and fails to execute. [3][4]
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.
Related techniques
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.
| Domain | ID | Name | Relationship / procedure |
|---|---|---|---|
| Enterprise | T1121 | Regsvcs/Regasm | Regsvcs/Regasm revoked by this object. |
| Enterprise | T1218 | System Binary Proxy Execution | This object subtechnique of System Binary Proxy Execution. |
Groups, software, and campaigns
S0331: Agent Tesla
Agent Tesla is a spyware Trojan written for the .NET framework that has been observed since at least 2014.[1][2][3]
All related ATT&CK context
Mitigation direction
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.
Imported snapshots across ATT&CK releases(2)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.2 | 3.0 | Current bundle | 081afbf50680… | ||
| 19.1 | 3.0 | Older bundle | 081afbf50680… |
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.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
- [1]MSDN Regsvcs
Microsoft. (n.d.). Regsvcs.exe (.NET Services Installation Tool). Retrieved July 1, 2016.
Open source URL - [2]MSDN Regasm
Microsoft. (n.d.). Regasm.exe (Assembly Registration Tool). Retrieved July 1, 2016.
Open source URL - [3]LOLBAS Regsvcs
LOLBAS. (n.d.). Regsvcs.exe. Retrieved July 31, 2019.
Open source URL - [4]LOLBAS Regasm
LOLBAS. (n.d.). Regasm.exe. Retrieved July 31, 2019.
Open source URL - [5]mitre-attackT1218.009Open source URL
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