Suspicious BugSleep Marker File in Public Directory

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1055Process Injection
Defense Evasion
- T1055Process Injection
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects creation of a file named a.txt in the C-Users-Public directory, an existence marker used by the BugSleep backdoor during its injection routine. The malware writes and checks this public path artifact to coordinate its shellcode injection into browser and remote access processes. Detecting the marker can surface the backdoor on the host.

Reporting behind it

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Suspicious BugSleep Marker File in Public Directory

Pivot detection · T1055 · 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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