Detecting Fileless Malware Techniques

When to Use

• EDR alerts indicate suspicious behavior from trusted system binaries (PowerShell, mshta, wmic, regsvr32)
• Investigating attacks that leave no traditional malware files on disk
• Analyzing WMI event subscriptions, registry-stored payloads, or scheduled task abuse for persistence
• Building detection rules for LOLBin (Living Off the Land Binary) abuse in enterprise environments
• Memory forensics reveals malicious code but no corresponding files exist on the filesystem

Do not use for traditional file-based malware; standard static and dynamic analysis methods are more appropriate for disk-resident malware.

Prerequisites

• Sysmon installed and configured with comprehensive logging (process creation, WMI events, registry changes)
• PowerShell Script Block Logging and Module Logging enabled
• Volatility 3 for memory forensics of fileless malware artifacts
• Process Monitor (ProcMon) for real-time system activity monitoring
• Windows Event Log access with adequate retention policies