Internet security company Network Associates Inc. says it will buy host intrusion-prevention software maker Entercept Security Technologies for $120 million in cash. Entercept's security apps combine traditional signatures to spot known attacks with behavioral rules that protect operating systems, databases, and applications from new attacks. Friday's announcement follows Network Associates' purchase earlier this week of privately held IntruVert Networks, which develops network-based intrusion-protection software, for $100 million in cash.

The proliferation of software vulnerabilities, coupled with increasingly fast worm attacks such as Code Red and the more recent Slammer, are increasing the demand for security applications that block these attacks, which often successfully bypass antivirus and firewall protection. "We heard our customers loud and clear," says Art Matin, president of McAfee Security, a division of Network Associates. "They have challenges with patch management and getting full knowledge of what's going on in the network."

The deals will effectively end Network Associates' strategic agreement with Internet Security Systems Inc., which licensed its intrusion-detection software to Network Associates.

While the acquisitions give Network Associates intrusion-prevention technology for networks, servers, applications, and databases, it's still missing intrusion-prevention software for desktops. Matin says the company will look at how it could be integrated with their existing desktop security applications, such as its desktop firewall. "The technology is definitely extendable," he says.

Network Associates expects to close both acquisitions in the next 45 days.

"With both acquisitions, it's clear Network Associates wants to dominate what's become known as the intrusion-prevention market," says Spire Security research director Pete Lindstrom. "These tools provide better, more proactive technology than antivirus or traditional intrusion-detection systems."

Entercept says it has 1,100 clients, including businesses and government agencies. Its customers include Arlington County, Va.; Corio; First Citizens Bank,; and New Century Mortgage. Until late January, Entercept held a key partnership with Cisco Systems, which helped the company win many of its accounts. That partnership ended when Cisco acquired Okena Inc., which makes intrusion-prevention software for desktops and servers, for $154 million.