A fileless loader is a type of malware delivery mechanism that operates entirely in a computer's memory, rather than writing files to disk. This approach allows attackers to bypass traditional antivirus and endpoint protection solutions, which typically scan for malicious files stored on a system. Fileless loaders often exploit legitimate system tools or vulnerabilities to inject malicious code directly into memory, making detection and forensic analysis much more challenging. They are commonly used in advanced persistent threats (APTs) and can serve as a launchpad for further malicious activities, such as downloading additional payloads, stealing data, or establishing remote access. Because they leave little to no trace on disk, defending against fileless loaders requires advanced behavioral monitoring and memory analysis.