Malware artifacts are the traces malicious software leaves behind on a system: files, running processes, scheduled tasks, registry keys, services, network connections, logs, and other evidence. Security tools look for these artifacts to detect infections, understand persistence, and reconstruct what an attacker did.
They matter because attackers often try to delete, rename, encrypt, or hide artifacts to slow incident response. Rootkits, for example, can filter file listings or process views so defenders see an incomplete picture. In real investigations, analysts compare endpoint telemetry, memory data, and external logs to find artifacts that the compromised host may be concealing. Tracking these traces helps confirm compromise even when the malware itself is not immediately visible.