Microsoft Build Engine Started an Unusual Process
editMicrosoft Build Engine Started an Unusual Process
editAn instance of MSBuild, the Microsoft Build Engine, started a PowerShell script or the Visual C# Command Line Compiler. This technique is sometimes used to deploy a malicious payload using the Build Engine.
Rule type: query
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
Severity: low
Risk score: 21
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Defense Evasion
Version: 4 (version history)
Added (Elastic Stack release): 7.7.0
Last modified (Elastic Stack release): 7.10.0
Rule authors: Elastic
Rule license: Elastic License
Potential false positives
editThe Build Engine is commonly used by Windows developers but use by non-engineers is unusual. If a build system triggers this rule it can be exempted by process, user or host name.
Rule query
editevent.category:process and event.type:(start or process_started) and process.parent.name:MSBuild.exe and process.name:(csc.exe or iexplore.exe or powershell.exe)
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Compile After Delivery
- ID: T1500
- Reference URL: https://attack.mitre.org/techniques/T1500/
Rule version history
edit- Version 4 (7.10.0 release)
-
- Formatting only
- Version 3 (7.9.1 release)
-
- Formatting only
- Version 2 (7.9.0 release)
-
-
Updated query, changed from:
process.parent.name:MSBuild.exe and process.name:(csc.exe or iexplore.exe or powershell.exe)
-