[metadata]
creation_date = "2020/03/25"
maturity = "production"
updated_date = "2020/12/09"

[rule]
author = ["Elastic"]
description = """
An 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.
"""
false_positives = [
    """
    The 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.
    """,
]
from = "now-9m"
index = ["winlogbeat-*", "logs-endpoint.events.*"]
language = "kuery"
license = "Elastic License"
name = "Microsoft Build Engine Started an Unusual Process"
references = ["https://blog.talosintelligence.com/2020/02/building-bypass-with-msbuild.html"]
risk_score = 21
rule_id = "9d110cb3-5f4b-4c9a-b9f5-53f0a1707ae6"
severity = "low"
tags = ["Elastic", "Host", "Windows", "Threat Detection", "Defense Evasion"]
type = "query"

query = '''
event.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)
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1027"
name = "Obfuscated Files or Information"
reference = "https://attack.mitre.org/techniques/T1027/"
[[rule.threat.technique.subtechnique]]
id = "T1027.004"
name = "Compile After Delivery"
reference = "https://attack.mitre.org/techniques/T1027/004/"


[rule.threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"

