A computer worm<span> is a standalone </span>malware computer program<span> that replicates itself in order to spread to other computers.</span><span>Often, it uses a </span>computer network<span> to spread itself, relying on security failures on the target computer to access it. Worms almost always cause at least some harm to the network, even if only by consuming </span>bandwidth<span>, whereas viruses almost always corrupt or modify files on a targeted computer. It can also shutdown the computer or network.</span>