Types
Worm
Self-replicating malware that spreads across networks and devices without user interaction, from classic internet worms to modern IoT botnets.
A worm is malware that self-propagates — copying itself to new hosts without needing a user to run it. Worms spread by exploiting vulnerabilities, abusing weak credentials, or riding network shares and removable media.
From internet worms to IoT botnets
The lineage runs from Morris (1988) and SQL Slammer through to today's IoT botnets like Mirai, which brute-forces default Telnet credentials to assemble massive DDoS swarms. Self-spreading capability also shows up bolted onto ransomware (e.g. WannaCry's use of EternalBlue).
Containment
Patch aggressively, segment networks to limit lateral movement, and disable unnecessary remote services. Worm outbreaks and their blast radius are documented on Cyber Breaches.