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: new_terms
Rule indices:
- winlogbeat-*
- logs-endpoint.events.process-*
- logs-windows.*
- logs-system.security*
Severity: low
Risk score: 21
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Tactic: Execution
- Data Source: Elastic Defend
- Data Source: System
Version: 314
Rule authors:
- Elastic
Rule license: Elastic License v2
Setup
editSetup
If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
events will not define event.ingested and default fallback for EQL rules was not added until version 8.2.
Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
event.ingested to @timestamp.
For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
Rule query
edithost.os.type:windows and event.category:process and event.type:start and process.parent.name:("MSBuild.exe" or "msbuild.exe") and
process.name:("csc.exe" or "iexplore.exe" or "powershell.exe")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Obfuscated Files or Information
- ID: T1027
- Reference URL: https://attack.mitre.org/techniques/T1027/
-
Sub-technique:
- Name: Compile After Delivery
- ID: T1027.004
- Reference URL: https://attack.mitre.org/techniques/T1027/004/
-
Technique:
- Name: Trusted Developer Utilities Proxy Execution
- ID: T1127
- Reference URL: https://attack.mitre.org/techniques/T1127/
-
Sub-technique:
- Name: MSBuild
- ID: T1127.001
- Reference URL: https://attack.mitre.org/techniques/T1127/001/