Security companies Webroot Software, Websense, and Sophos are also targeted in the suit, which claims they are violating two patents.
M86 makes second acquisition in the past year, buying secure SaaS and Web gateway provider Finjan.
New SecureTweets plug-in can protect people from worms, Trojans, and other malware attacks spread through Twitter, Gmail, MySpace, and other sites.
Huge botnet hosted in the Ukraine is being used to send spam, record keystrokes, and copy files of infected computers running Windows XP, researchers say.
The company, which sells Web gateway security software to the corporate market, plans to expand its sales and marketing infrastructure with the money.
IE remains the most widely used browser, and version 8 is much safer than its predecessors; these six free add-ons help IE 8 users avoid malware and other Web dangers.
New, dangerous combination of banking Trojan and exploit toolkit enables criminals to transfer money out of accounts while users are logged into the bank site, without them knowing it.
Apple to give away cases to deal with its touchy iPhone trouble, while FCC's indecency rules get slammed by court. Also: Juggling passwords.
These sophisticated new Web attacks vanish upon second visits and also know how to block search engines.
Share a lot? Here's a guide to the security and privacy problems that users of Facebook and Twitter encounter, and what they can do about it.