Originally written by Symantec and sold as Symantec Antivrus for Macintosh, it became part of the "Norton" branded products sold by Symantec after they acquired Peter Norton Computing. Norton Anti-Virus became a popular product on DOS, Windows, and Macintosh (SAM was renamed to NAV in 1998) and battled the then-new threat of malicious software. In 2015, Symantec unified their security product lineup under the single "Norton Security" product. It was also bundled with Norton SystemWorks.