Malicious AMSI and ETW Bypass via In-Memory Patching (via ps_script)

ATT&CK techniques

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

What it detects

This rule detects PowerShell in-memory tampering with AMSI and ETW to blind endpoint defenses, used by the MIMICRAT loader. Observed in Elastic Security Labs analysis where amsiInitFailed forcing, EventProvider m_enabled zeroing, and ScanContent Marshal.Copy patching disable scanning and telemetry before staging the RAT.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

Malicious ETW Disabling via COMPlus_ETWEnabled Environment Variable

Suspicious CrazyHunter BYOVD Driver Drop in Public Directory

Suspicious Execution of cfmon.exe Masquerading as ctfmon via CharmingCypress

Suspicious SELinux Enforcement Disabled via Setenforce Command Line (via process_creation)

Suspicious SELinux and Firewall Disabling on Linux by Cryptominer (via process_creation)

Suspicious Windows Defender Exclusion of User Profile via PowerShell (via process_creation)

Malicious Vulnerable Driver Service Creation for BYOVD (via process_creation)

Malicious Microsoft Defender Disabled via Registry DisableAntiSpyware (via process_creation)

Suspicious Termination of Defender Tray Process via Taskkill

Malicious AMSI and ETW Bypass via In-Memory Patching (via ps_script)

Pivot detection · T1685 · 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 →