Windows Change Default File Association For No File Extension

The following analytic detects attempts to change the default file association for files without an extension to open with Notepad.exe. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line patterns and registry modifications. This activity is significant as it can indicate an attempt to manipulate file handling behavior, a technique observed in APT and ransomware attacks like Prestige. If confirmed malicious, this could allow attackers to execute arbitrary code by tricking users into opening files, potentially leading to system compromise or data exfiltration.