What is fileless malware?

Fileless malware operates in memory and abuses legitimate system tools — such as PowerShell or WMI — rather than writing a malicious file to disk. This makes it harder for traditional, file-scanning antivirus to detect.

While fileless techniques are used to gain and maintain access, the eventual impact still lands on stored data. Elastio detects the resulting corruption inside the data regardless of how the attacker executed.

Last updated May 27, 2026