Detection Strategy for T1542.004 Pre-OS Boot: ROMMONkit

Technique Detected:  ROMMONkit | T1542.004

ID: DET0175
Domains: Enterprise
Analytics: AN0497
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN0497

Detection of anomalous ROMMON image changes or upgrades, unexpected reboots following firmware updates, and unauthorized use of firmware upgrade commands or TFTP transfers. Correlation of config modification, privilege escalation, and boot cycle anomalies provides visibility into ROMMON tampering attempts.

Log Sources
Data Component Name Channel
Firmware Modification (DC0004) networkdevice:config Log entries indicating ROMMON image upgrade commands (boot system, upgrade rom-monitor)
OS API Execution (DC0021) networkdevice:syslog Unexpected reload, crashinfo, or boot message not tied to scheduled maintenance
Network Connection Creation (DC0082) NSM:Flow Outbound or inbound TFTP file transfers of ROMMON or firmware binaries
Mutable Elements
Field Description
ApprovedROMMONVersions Baseline ROMMON image versions authorized for the environment
TimeWindow Correlation window between ROMMON update command, TFTP file transfer, and device reboot
AdminUserContext Expected privileged accounts allowed to execute ROMMON upgrade commands