Suspicious MSBuild Spawned by PowerShell (via process_creation)
- Product
- windows
- Category
- process_creation
- Author
- HuntRule
- Published
- 2026-10-25
- Updated
- 2026-10-25
ATT&CK techniques
Execution → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects the .NET build engine MSBuild.exe being spawned as a child of PowerShell, a living-off-the-land pattern used to execute code outside normal build workflows. The SHADOW#REACTOR campaign abused MSBuild to run an in-memory Remcos payload.
Reporting behind it
- securonix.comhttps://www.securonix.com/blog/shadowreactor-text-only-staging-net-reactor-and-in-memory-remcos-rat-deployment/
- attack.mitre.orghttps://attack.mitre.org/techniques/T1127.001/
- fortinet.comhttps://www.fortinet.com/blog/threat-research/phishing-campaign-deploys-javascript-driven-purelogs-variant-to-steal-sensitive-data
- attack.mitre.orghttps://attack.mitre.org/techniques/T1055/012/
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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