Malware - know your nemesis
Malware, a portmanteau of "malicious" and "software", is an umbrella term for software applications and programs intended to cause disruption to computer operation, gather sensitive information, or gain access to private computer systems. It can appear in the form of code, scripts or active content (drive-by downloads), or as part of other seemingly-legitimate software. Some malware is disguised as genuine software, and may come from an official website in the form of a useful or attractive program which has the harmful malware embedded in it along with additional tracking software that gathers marketing statistics.