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

Malicious Microsoft Defender Real-Time Monitoring Disabled via Set-MpPreference (via process_creation)

Suspicious Windows Defender Exclusion Added via PowerShell via Process Creation (via process_creation)

Malicious TCC AppleEvents Reset via Tccutil

Suspicious ESXi Management Agent Stop via vpxa init Script (via process_creation)

Malicious ESXi Firewall Disable via esxcli (via process_creation)

Malicious ESXi Syslog Redirection to tmp via esxcli

Suspicious Windows Defender Exclusion Enumeration via reg query (via process_creation)

Malicious Windows Defender Exclusion Added via PowerShell (via process_creation)

Malicious BYOVD EDR Kill via Renamed GMER Driver by Agonizing Serpens

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 →