Finjan has sued five rival security companies, including Symantec and McAfee, claiming it holds crucial patents used by popular antivirus products and security services.

The lawsuit was filed Monday in the U.S. District Court for the District of Delaware. Also named are Webroot Software, Websense and Sophos.

Finjan alleges that flagship products from these companies violate two patents that Finjan has held for about a decade. Formerly a technology vendor itself, Finjan sold most of its assets last November to another security company, M86, but held onto its patent portfolio, which it is now trying to turn into a moneymaker. Finjan owns about a dozen patents, all related to computer security.

In 2008, Finjan won a jury verdict against Secure Computing (now owned by McAfee), awarding it damages for patent infringement by Secure Computing's Webwasher and CyberGuard TSP software. Jurors awarded Finjan US$9.2 million in damages, but a federal judge later increased that award to $13.8 million.

Monday's lawsuit involves one of the patents covered in the Secure Computing case that relates to network-based virus protection. It also names a second patent, a "system and method for protecting a client during runtime from hostile downloadables," that covers Finjan's desktop antivirus claims.

The company asked the court to award unspecified financial damages and an injunction preventing the companies from selling their products, which include McAfee's Web Gateway and VirusScan software, and Symantec's Brightmail Gateway and Norton Antivirus.

Symantec and McAfee declined to comment on the suit. Webroot, Websense and Sophos (which was acquired by Apax Partners in May) could not immediately be reached for comment.