Settra ransomware: domain-like _win64.exe launch to mass .locked encryption

Arnold Chan@slaz

•updated Sep 18, 2026•0•0•2

This rule detects potential ransomware activity by correlating three distinct events: the execution of a suspicious, potentially obfuscated binary (matching a specific naming pattern of _win64.exe) from an untrusted location (e.g., Temp, AppData, Downloads), followed by a high volume of file modifications or renames with specific ransomware-related extensions (.locked), and the dropping of a known ransom note file (RESTORE_FILES.txt) within a short 15-minute time window.