Several users’ computers are no longer responding normally and sending out spam email to the
users’ entire contact list. This is an example of which of the following?

A.
Trojan virus

B.
Botnet

C.
Worm outbreak

D.
Logic bomb

Explanation:
A worm is similar to a virus but is typically less malicious. A virus will usually cause damage to the
system or files whereas a worm will usually just spread itself either using the network or by
sending emails.
A computer worm is a standalone malware computer program that replicates itself in order to
spread to other computers. Often, it uses a computer network to spread itself, relying on security
failures on the target computer to access it. Unlike a computer virus, it does not need to attach
itself to an existing program. Worms almost always cause at least some harm to the network, even
if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a
targeted computer.