Suspicious VMware Guest Operation Output Staging in vmware-system Temp Directory (via file_event)

ATT&CK techniques

Execution → Lateral Movement

Recon
Resource Dev
Initial Access
Execution
- T1059Command and Scripting Interpreter
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
- T1021Remote Services
Collection
C2
Exfiltration
Impact

What it detects

This rule detects files being written under the Windows Temp vmware-system directory used by PowerCLI Invoke-VMScript guest operations. Fire Ant leveraged unauthenticated PowerCLI guest command execution from compromised vCenter and ESXi infrastructure, redirecting command output into this staging path inside targeted virtual machines. Legitimate administrative use of Invoke-VMScript can also generate these artifacts.

Reporting behind it

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Suspicious VMware Guest Operation Output Staging in vmware-system Temp Directory (via file_event)

Pivot detection · T1059 · 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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