Microsoft Build Engine Using an Alternate Name

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An instance of MSBuild, the Microsoft Build Engine, was started after being renamed. This is uncommon behavior and may indicate an attempt to run unnoticed or undetected.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*
  • logs-windows.*
  • endgame-*

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

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Defense Evasion
  • Elastic Endgame

Version: 102 (version history)

Added (Elastic Stack release): 7.7.0

Last modified (Elastic Stack release): 8.6.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

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The Build Engine is commonly used by Windows developers but use by non-engineers is unusual.

Investigation guide

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Rule query

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process where event.type == "start" and
process.pe.original_file_name == "MSBuild.exe" and not process.name
: "MSBuild.exe"

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 102 (8.6.0 release)
  • Formatting only
Version 101 (8.5.0 release)
  • Updated query, changed from:

    process where event.type in ("start", "process_started") and
    process.pe.original_file_name == "MSBuild.exe" and not process.name
    : "MSBuild.exe"
Version 12 (8.4.0 release)
  • Formatting only
Version 10 (8.2.0 release)
  • Formatting only
Version 9 (7.16.0 release)
  • Formatting only
Version 8 (7.13.0 release)
  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
    process.pe.original_file_name:MSBuild.exe and not process.name:
    MSBuild.exe
Version 7 (7.12.0 release)
  • Formatting only
Version 6 (7.11.2 release)
  • Formatting only
Version 5 (7.11.0 release)
  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
    (process.pe.original_file_name:MSBuild.exe or
    winlog.event_data.OriginalFileName:MSBuild.exe) and not process.name:
    MSBuild.exe
Version 4 (7.10.0 release)
  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
    (pe.original_file_name:MSBuild.exe or
    winlog.event_data.OriginalFileName:MSBuild.exe) and not process.name:
    MSBuild.exe
Version 3 (7.9.1 release)
  • Formatting only
Version 2 (7.9.0 release)
  • Updated query, changed from:

    (pe.original_file_name:MSBuild.exe or
    winlog.event_data.OriginalFileName: MSBuild.exe) and not process.name:
    MSBuild.exe and event.action: "Process Create (rule: ProcessCreate)"