Suspicious csc.exe Spawned by Document Reader for Process Injection

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 the C# compiler being launched by the hpreader host process, which Ghost Crypt abuses as an injection target using a debugger-based process hypnosis technique to load PureRAT. A document reader spawning csc.exe is not expected behavior and points to code injection into a benign child process.

Reporting behind it

Related detections9 linkedT1055.012 — drag to rearrange

Suspicious RegAsm Execution Spawned by Script Host for Process Hollowing (via process_creation)

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

Suspicious RegAsm Spawned as Process Hollowing Target

Suspicious SearchIndexer Process Started by Non-Service Parent for Hollowing

Suspicious Browser Updater Binary Spawned by AutoIt for Process Hollowing

Suspicious DotNet Utility Spawned by Script Host for Process Hollowing via Command Line

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 csc.exe Spawned by Document Reader for Process Injection

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.

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 →