This document discusses malware and computer viruses. It defines malware as malicious software like viruses and spyware that infect computers and smartphones. Malware can cause issues like identity theft and crashing computers. The document recommends keeping antivirus and firewall software up to date, avoiding suspicious websites, and backing up data to help prevent malware infections. It also provides signs of a potential malware infection like slow computer performance, repeated errors, and unwanted software changes. The document outlines different types of viruses like computer viruses that infect other programs, email viruses sent through attachments, Trojan horses that masquerade as other programs, and worms that spread through networks.