Fileless Malware

Fileless malware is a type of malicious software that operates without leaving traditional files on a system's disk, instead residing in memory or leveraging legitimate system tools and processes to execute attacks. It typically exploits vulnerabilities in applications or operating systems to inject code directly into RAM, making it harder to detect with conventional antivirus solutions that rely on file scanning. This technique allows attackers to maintain persistence, steal data, or perform other malicious activities while evading detection.

Also known as: Memory-based malware, Non-malware attacks, Living-off-the-land techniques, In-memory malware, Fileless attacks

Why learn Fileless Malware?

Developers should learn about fileless malware to enhance security awareness and build more resilient applications, especially in environments handling sensitive data or critical infrastructure. Understanding this concept is crucial for implementing security measures like memory protection, behavioral analysis, and least-privilege access to mitigate risks. It's particularly relevant in cybersecurity roles, incident response, and when developing software for high-security industries like finance or healthcare.

Learning Resources

• docs: MITRE ATT&CK: Fileless Malware
• tutorial: SANS Institute: Detecting Fileless Malware
• docs: CrowdStrike: What is Fileless Malware?
• video: YouTube: Fileless Malware Explained
• course: Cybrary: Malware Analysis Course