What is Fileless Malware?
Fileless Malware Definition: Malicious software that operates entirely in memory or leverages legitimate system tools rather than installing files on a disk.
Understanding Fileless Malware
Fileless Malware represents a particularly sneaky type of attack because it doesn't install actual files on your hard drive that antivirus tools can easily detect. Instead, it operates entirely in memory, often by hijacking legitimate system tools and processes. Think of traditional malware as leaving footprints on the beach, while fileless malware walks in the water leaving no traces behind. It might exploit PowerShell, Windows Management Instrumentation, or browser vulnerabilities to directly inject malicious code into RAM. Since it doesn't write to disk, traditional file-scanning security tools often miss it completely. The code typically vanishes when the system reboots—but by then, attackers have usually established persistence through registry modifications, scheduled tasks, or other means. Defending against it requires behavior-based detection rather than signature-based approaches that most traditional security products use.