Ransomware
Malware that encrypts data and demands payment for the decryption key.
Ransomware encrypts data and demands payment for the key, and it has evolved past simple encryption: double extortion exfiltrates data first and threatens to leak it, so good backups alone no longer guarantee safety, and Ransomware-as-a-Service lets low-skill affiliates run campaigns. Offline, immutable backups remain the single most effective recovery control, paired with fast patching, MFA, network segmentation to limit spread, and EDR to catch the intrusion before encryption begins.