Symantec has bought security vendor WholeSecurity for an undisclosed sum.

Symantec will combine WholeSecurity's "behaviour-based" security software with its own consumer and enterprise security products, the company said.

Products such as Symantec's Norton Internet Security suite use samples of code, or signatures, to identify malicious software. WebSecurity's software, on the other hand, determines whether potential viruses are malicious based on the things they are trying to do. As such, the behaviour-based approach protect computers from unidentified threats.

WholeSecurity's Confidence Online product suite includes security software for Web applications and PCs, and the company also sells anti-phishing products. WholeSecurity employs "less than 100" employees, none of whom are expected to be laid off.

"We expect WholeSecurity's family of solutions to be a core component of Symantec's baseline consumer security and enterprise desktop solutions," said Enrique Salem, senior VP at Symantec.

Whole Security's CEO J. Peter Selda said: "We have been the first line of defense for our customers, protecting them against new forms of malicious threats before signatures can be created. Combining our behaviour-based technology with Symantec's industry leading solutions will allow us to deliver this capability to a much broader audience and move us further toward our vision of providing zero-hour protection for every endpoint."