Sophisticated malware that operates entirely in memory, leaving no files for traditional antivirus to detect.
Fileless malware operates entirely in system memory without writing traditional files to disk, evading signature-based antivirus that scans files. It exploits legitimate system tools (PowerShell, WMI, macros) to execute malicious code, leaving minimal forensic traces. Fileless attacks often start through phishing or exploit kits, then use living-off-the-land techniques to persist and spread. Detection requires behavioural analysis, memory scanning, and monitoring of legitimate tool abuse.
Why It Matters
The DSC Perspective:
Fileless malware defeats traditional antivirus. Modern endpoint protection (EDR) with behavioural detection is essential. This is why 'we have antivirus' is no longer an adequate security answer.