A computer worm is a malware that spreads copies of its code from one device to another. The program replicates without human interaction or attaching itself to other software programs. Worms infect systems through vulnerable software and malicious attachments in spam emails and instant messages. The self-replicating malware use parts of an operating system that are automatic and invisible to users. Once worms attack a system, they leverage file or information transport features to travel unaided. Fortunately, victims can detect worms when the uncontrolled replication consumes system resources and slows or halts other tasks.