Malicious Fseventsd Masquerade in Users Shared Directory via File Event

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1036.005Match Legitimate Resource Name or Location
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects creation of a hidden fseventsd named file inside the Users Shared directory which the macOS pirate ship campaign drops to masquerade its payload as a legitimate filesystem events daemon artifact. The genuine fseventsd store does not live in Users Shared so this file placement is a defense evasion masquerade.

Reporting behind it

Related detections9 linkedT1036.005 — drag to rearrange

Suspicious Loading of Masqueraded EndpointDlp.dll Backdoor

Suspicious svchost.exe Execution from Public Directory (via process_creation)

Suspicious Process Masquerading as apached via GobRAT Bulbature Implant

Suspicious MicrosoftEdgeUpdate Launched with Dat Config File

Malicious Scheduled Task Masquerading as Defender NisSrv via Schtasks

Malicious PowerShell Masquerading as Windows Terminal in ProgramData (via process_creation)

Suspicious Csrss Process Masquerading Outside System32 (via process_creation)

Suspicious Mimilite Credential Dumper Execution Writing KB-Named Output

Suspicious PikaBot Autorun Persistence Pointing to AppData Microsoft Dropzone via registry_set

Malicious Fseventsd Masquerade in Users Shared Directory via File Event

Pivot detection · T1036.005 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

Full detection rule

Unlock this rule to view and copy it

The detection logic is included with a plan. Everything else — context, mappings and implementation details — stays free on this page.

Sign in for 3 free unlocks

Signing in gives you 3 unlocks to spend on any rule in the library. No card, and they do not expire.

Also included

Unlocked rules convert on this page — to Splunk SPL or Splunk — Raw Index SPL or Microsoft Sentinel KQL or Microsoft Sentinel ASIM ASIM KQL or Microsoft Defender XDR KQL or Elastic Security KQL or Elastic Security Lucene or Elastic Security ES|QL or CrowdStrike Falcon CQL or SentinelOne PowerQuery or Palo Alto Cortex XDR XQL or Carbon Black Cloud Platform Search or Carbon Black EDR Process Search or Google Security Operations UDM Search or IBM QRadar AQL or Sumo Logic Cloud SIEM Rules expression or Rapid7 InsightIDR LEQL or Graylog Search or OpenSearch Lucene or OpenSearch PPL PPL or Grafana Loki LogQL or SQLite SQL or Zircolite SQLite — with the log-source profile the engine picked, the field map it used, and everything it could not express. Converting a rule you have unlocked costs no further credit.

See it run on a free rule →Convert your own rule →