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 look to be downloading a suspicious fiile from an external source, and examining files on your computer to see if they match the software's idea of what malware looks like.
Anti-virus
software can only recognise malware if it is substantially similar to samples that the anti-virus developer has already analysed. 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.
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