Antivirus software is computer programs that attempt to identify, neutralize or eliminate malicious software. Antivirus is so named because the earliest examples were designed exclusively to combat computer viruses; however most modern antivirus software is now designed to combat a wide range of threats, including worms, phishing attacks, rootkits, trojan horses and other malware. Antivirus software typically uses two different approaches to accomplish this:

• Examining (scanning) files to look for known viruses matching definitions in a virus dictionary, and
• Identifying suspicious behavior from any computer program which might indicate infection.