The rule "Suspicious Startup Shell Folder Modification" serves as a detection mechanism for unauthorized modifications in Windows startup shell folders through the registry. Such modifications are often attempted by malware to maintain persistence on an infected system, manipulating the default directories that control application startup behaviors. The rule utilizes the Elastic Query Language (EQL) to identify changes in specific registry paths associated with startup folders, checking for suspicious strings that would typically not appear in legitimate configurations. It covers multiple paths across user and machine contexts, enabling the detection of abnormalities that traditional security measures may overlook due to their atypical nature. This allows for quicker mitigation efforts against potential threats that could hijack system startup routines or increase the attack surface by executing malicious processes with elevated privileges. The investigation process outlined emphasizes examining execution chains, validating the legitimacy of changes against known legitimate activities, and scrutinizing adverse impacts on endpoints.