Microsoft Build Engine Started by a Script Process

An instance of MSBuild, the Microsoft Build Engine, was started by a script or the Windows command interpreter. This behavior is unusual and is sometimes used by malicious payloads.

Rule type: eql

Rule indices:

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: None

Tags:

Version: 14

Rule authors:

Rule license: Elastic License v2

## Setup

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 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

process where event.type == "start" and
  (process.name : "MSBuild.exe" or process.pe.original_file_name == "MSBuild.exe") and
  process.parent.name : ("cmd.exe", "powershell.exe", "pwsh.exe", "powershell_ise.exe", "cscript.exe", "wscript.exe", "mshta.exe")