Fileless Malware
Fileless Malware: Malware that operates primarily in memory and abuses legitimate system tools. Defense requires robust preventionPreventionMeasures intended to stop security incidents or attacks before they occur., meaningful loggingLoggingThe recording of security-relevant events so activity can be monitored, investigated, and audited., timely detectionDetectionThe capability to identify suspicious activity, attacks, or policy violations in time., and clearly defined response measures.
How it works and where it fits
Fileless Malware is classified by its behavior and purpose: execution, persistence, propagation, command, and harmful effect are distinct phases. Not every variant uses every phase, and the same malicious component may arrive through different delivery mechanisms or carry different payloads. Analysis therefore considers process, identity, and network behavior in addition to file signatures.
Practical security relevance
Operational handling should address the entire attack chain. Isolating affected systems is only one step; responders must also investigate the entry point, persistence mechanisms, stolen credentials, and possible lateral movement. Recovery is dependable only after malicious components are removed, root causes are closed, relevant secrets are rotated, and monitoring is tuned for renewed activity.
Related concepts
- MalwareMalwareUmbrella term for software with malicious or unwanted functionality.: Umbrella term for software with malicious or unwanted functionality.
- Trojan HorseTrojan HorseMalware that masquerades as legitimate or useful software.: Malware that masquerades as legitimate or useful software.
- RansomwareRansomwareMalware that encrypts data or locks systems and demands a ransom.: Malware that encrypts data or locks systems and demands a ransom.
- Command and ControlCommand and ControlCommunication infrastructure used by attackers to control compromised systems.: Communication infrastructure used by attackers to control compromised systems.