John is analyzing a recent malware infection on his company network. He discovers malware that can spread rapidly via vulnerable network services and does not require any interaction from the user. What best describes this malware?

Worms spread themselves via vulnerabilities, making this an example of a worm. A virus is software that self-replicates. A logic bomb executes its malicious activity when some condition is met. A Trojan horse combines malware with a legitimate program.