Malicious ESXi Secure Boot Bypass via execInstalledOnly Disable

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 an esxcli command disabling the execInstalledOnly kernel setting on an ESXi host, matching UNC3944 tampering that allows unsigned binaries to run so the actor can deploy ransomware and offline tooling. Turning off this protection removes a core defense against untrusted code on the hypervisor.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

Windows Defender Tampering via Set-MpPreference and Exclusions

Suspicious Windows Defender Real-Time Protection Disabled via Policy Registry by Cephalus Ransomware

Suspicious Microsoft Defender Path Exclusion of User Directories (via process_creation)

Malicious Windows Defender Tampering via Set-MpPreference (via process_creation)

Malicious Container Runtime Tampering via chmod on runc (via process_creation)

In-Memory AMSI or ETW Bypass in PowerShell (via process_creation)

Malicious Microsoft Defender Critical Security Components Disabled - Command (via process_creation)

Malicious Microsoft Defender Service Deactivation Attempt - Command (via process_creation)

Malicious Wdigest Authentication Enabled - Reg via Command (via process_creation)

Malicious ESXi Secure Boot Bypass via execInstalledOnly Disable

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 →