Suspicious Csrss Process Masquerading Outside System32 (via process_creation)

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 a process named csrss.exe running from any location other than the System32 or SysWOW64 directories, a masquerade used by the Glupteba packed installer to blend with the legitimate Client Server Runtime Subsystem. The genuine csrss.exe only ever launches from System32, so an off path copy indicates a spoofed loader attempting to hide malicious execution.

Reporting behind it

Related detections9 linkedT1036.005 — drag to rearrange

Suspicious Mimilite Credential Dumper Execution Writing KB-Named Output

Suspicious PikaBot Autorun Persistence Pointing to AppData Microsoft Dropzone via registry_set

Malicious Live Ledger Persistence via Realter HD Audio Run Key via registry_set

Malicious Live Ledger Stealer Execution via Ledger Lives Masquerade via process_creation

Suspicious Svchost Masquerade Execution from Non-System Path

Suspicious Vidar Payload Execution from AI-Themed DeepSeek Lure Path

Malicious Sapphire Sleet LaunchDaemon Masquerading as Google WebKit Service (via file_event)

Malicious UNC1549 OneDrive-Masquerading Run Key Persistence (via registry_set)

Suspicious macOS LaunchDaemon Masquerading as Apple System Updater

Suspicious Csrss Process Masquerading Outside System32 (via process_creation)

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 →