Detect Abuse of vSphere Installation Bundles (VIBs) for Persistent Access

ID: DET0535
Domains: Enterprise
Analytics: AN1475
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN1475

Malicious VIB installation for persistence via esxcli software vib install using --force or --no-sig-check, enabling custom startup scripts or firewall rules. Behavior chain: (1) unsigned/suspicious VIB installation → (2) startup script or binary placed in persistent boot path → (3) persistence across reboot via /etc/rc.local.d or other boot hook).

Log Sources
Data Component Name Channel
Application Log Content (DC0038) esxi:esxupdate /var/log/esxupdate.log contains VIB installed with `--force` or `--no-sig-check` and non-standard acceptance levels
Command Execution (DC0064) esxi:shell `esxcli software vib install` with `--force` or `--no-sig-check` from shell history or `shell.log`
File Modification (DC0061) linux:fim Changes to /etc/rc.local.d/local.sh or creation of unexpected startup files in persistent partitions (/etc/init.d, /store, /locker)
Mutable Elements
Field Description
AcceptanceLevel Some environments may intentionally permit CommunitySupported or unsigned VIBs—filter by known allowed publishers.
InstallCommandThreshold Set alerting thresholds for frequency of VIB install attempts per host/user/time window.
StartupPathRegex Tune regex for monitoring startup file locations based on ESXi image customization.