This detection rule aims to identify Denial of Service (DoS) attempts against Cisco systems by monitoring specific shutdown commands and configuration register changes that could lead to a system reboot or altered operational state. The keywords used for detection specifically include terms associated with shutting down the system and changing configuration registers to values 0x2100 and 0x2142, which are indicative of a boot from ROM or bypassing the startup configuration. The detection utilizes logs sourced from Cisco's AAA service, which is responsible for authentication, authorization, and accounting. The rule is designed to alert on potential unauthorized access attempts or attempts to disrupt the normal functioning of Cisco devices. However, it is important to be aware of legitimate administrator actions that may trigger false positives, though such events are expected to be infrequent. This medium-level detection is crucial for maintaining system integrity and availability.