Antivirus

Software that attempts to protect a device from being taken over by malicious software (or “malware "). Viruses were some of the first and most prevalent forms of malware; they were named viruses to reflect the way they would spread from device to device. These days most antivirus software concentrate on warning you if you are downloading a suspicious file from an external source, and examining files on your computer to see if they match the software's idea of what malware looks like.

Antivirus software can only recognize malware if it is similar to samples that the antivirus developer has already analyzed. This makes it far less effective at combating targeted malware designed to infiltrate a particular community or person, rather than more widespread strains of malware. Some advanced malware can also actively attack or conceal itself from antivirus software.