Detection Strategy for T1542.005 Pre-OS Boot: TFTP Boot

Technique Detected:  TFTP Boot | T1542.005

ID: DET0582
Domains: Enterprise
Analytics: AN1603
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN1603

Detection of unauthorized changes to boot configurations pointing to TFTP servers, unusual firmware loads during netbooting, or suspicious TFTP traffic. Correlation of boot config modifications, command history logs, and unexpected system image hashes provides detection coverage for adversaries attempting to persist via malicious TFTP boot images.

Log Sources
Data Component Name Channel
Command Execution (DC0064) networkdevice:config Configuration changes referencing 'boot system tftp' or modification of startup-config pointing to external TFTP servers
Firmware Modification (DC0004) networkdevice:syslog Boot information log showing image loaded from TFTP server instead of local storage
Network Connection Creation (DC0082) NSM:Flow Unexpected inbound/outbound TFTP traffic for device image files
Mutable Elements
Field Description
ApprovedTFTPServers Whitelist of TFTP servers authorized for netbooting in the environment
TimeWindow Detection correlation window between config change, TFTP activity, and system reboot
BaselineBootImageHash Expected system image hashes to validate integrity of boot images loaded via TFTP