Suspicious .NET Utility Launched as Process Injection Target (via process_creation)

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1055.012Process Hollowing
Defense Evasion
- T1055.012Process Hollowing
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects MSBuild.exe or RegAsm.exe running without any project, solution or assembly argument, the state in which FakeBat IDAT loader and Payk RunPE hollow these signed .NET utilities to host SectopRAT. Legitimate invocations reference a build file or assembly, so argument-less execution indicates process hollowing. This is the injection stage of Google Ads malvertising via MSIX.

Reporting behind it

Related detections9 linkedT1055.012 — drag to rearrange

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Suspicious Outbound Network Connection from msiexec.exe (via network_connection)

Suspicious Outbound Connection from tracerpt.exe after Process Hollowing (via network_connection)

Suspicious AddInProcess32 Outbound Connection after Process Hollowing

Suspicious microsoftedgeupdatecore Outbound Connection from Wrong Path

Suspicious RegAsm or AppLaunch Outbound Connection after Injection

Suspicious .NET Utility Launched as Process Injection Target (via process_creation)

Pivot detection · T1055.012 · 9 related

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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