Competitors, in terms of market share in this study, include antivirus products from McAfee, Trend Micro, and Kaspersky Lab.

[10] By early 1991, U.S. computers were invaded by hundreds of foreign virus strains and corporate PC infection was becoming a serious problem.

[11] Ads for the product, with suggested retail $129, featured Norton in his crossed-arm pose, wearing a pink shirt and surgical mask covering his nose and mouth.

Due to bug in the software, the original Norton Antivirus 1.0 does not repair infected files or boot sectors properly.

This is very handy in case a virus that its definitions do not detect, overwrite this information or move the boot sector to a different location of the hard disk.

Unlike other antivirus software products for MS-DOS and early Windows, which will only notify you to turn off your computer, but continue anyway, Auto-Protect or the main program will scan for viruses in memory before loading themselves.

The Classic edition is marketed alongside Norton AntiVirus 2009, which does include spyware and adware detection.

To further facilitate detection of zero-day malware, Bloodhound disassembles a variety of programming languages, and scans code for malicious instructions using predefined algorithms.

This release adds real-time exploit protection, preventing attackers from leveraging common browser and application vulnerabilities.

Other features include Norton Insight, a whitelisting technology which cuts scanning times by mapping known safe files using information from an online database.

The Gaming edition provides finer control over when Norton downloads updates and allows components of the suite to be disabled either manually or automatically when the computer enters full-screen mode.

Norton Insight can present users with information about the origins, activities, and performance of applications along with reputation data.

[27] The FBI confirmed the active development of Magic Lantern, a keylogger intended to obtain passwords to encrypted e-mail and other documents during criminal investigations.

Magic Lantern was first reported in the media by Bob Sullivan of MSNBC on 20 November 2001 and by Ted Bridis of the Associated Press.

Concerns around this whitelisting include uncertainties about Magic Lantern's full surveillance potential and whether hackers could subvert it and redeploy it for purposes outside of law enforcement.

[31][32] On January 28, 2010 Symantec Anti-virus update marked Spotify as a Trojan Horse disabling the software across millions of PCs.

Another incident occurred in May 2007, when Norton AntiVirus flagged components of the Pegasus email client as malicious, rendering the program corrupted.

The company released a statement, stating they expected to deliver a repair patch to affected users by Monday, July 31, 2006.

[42] However, neither route of uninstallation will remove subscription data, preserved to prevent users from installing multiple trial copies.

On March 9, 2009, some users of Norton AntiVirus 2006 and 2007 experienced a firewall warning stating a Norton-associated file, "PIFTS.exe", was trying to connect to the Internet.

[44] Although this file was revealed to be a harmless diagnostic patch, the program gained attention in the media when Symantec removed posts from their forum concerning PIFTS.

[45] The SANS Internet Storm Center claimed to have spoken to a Symantec employee who has confirmed that "the program is theirs, part of the update process and not intended to do harm.

"[46] Graham Cluley, a consultant from antivirus vendor Sophos found PIFTS connected to a Symantec server, forwarding product and computer information.

[45] Cole stated the purpose of the update was to help determine how many customers would need to be migrated to Windows 7-compatible versions of Norton AntiVirus.

PIFTS apparently was released without a digital signature to verify its identity, causing firewalls to prompt for permission when it attempted to connect to the Internet.

[49] Symantec has been criticized by some consumers for perceived ethical violations, including allegations that support technicians would tell customers that their systems were infected and needed a technician to resolve it remotely for an extra fee, then refuse to refund when the customers alleged their systems had not actually been infected.

[51] Norton AntiVirus 11 also includes the ability to scan within compressed or archived files, such as Time Capsule volumes.

Norton AntiVirus Dual Protection for Mac is intended for Macintosh users with Windows running on their systems, using Boot Camp or virtualization software such as VMware Fusion.

[60] Dennis Technology Labs (in tests sponsored by Symantec) confirms the performance and effectiveness of Norton 2011 and 2012 lines.

[61] On 14 August 2013 the Prime Minister of New Zealand John Key addressed what he identified as "misinformation" surrounding the GCSB Amendment Bill, claiming that the actions of the Government Communications Security Bureau were analogous to Norton AntiVirus.