The Santa Clara, California.-based network security and management software firm said it had detected a "denial-of-service" blitz Wednesday night and took unspecified action to protect itself right away.

Such attacks are designed to disrupt a site by swamping it with phony traffic that keeps clients and visitors out.

"No penetration into the corporate network took place and no data was compromised," said company spokeswoman Dana Lengkeep. "We are still investigating the origin of it."

The company was looking in particular at a program that emerged Wednesday on Bugtraq, a widely followed computer security E-mail list. "That appears to be at least once of the problems," Lengkeep said, adding that malicious code also may have been posted on other Web sites frequented by hackers.

The program on Bugtraq purported to exploit a flaw in Berkeley Internet Name Domain, or BIND, software that steers up to 90 per cent of traffic on the Internet.

But it was actually a "trojan," designed by hackers to attack Network Associates, which discovered the flaw in BIND and joined in publicizing it on Monday, computer security experts said.

"This is (hackers') little way of kind of slapping back," said Robin Matlock of San Jose, Calif.-based Entercept Security Technologies Inc., which develops software to protect Web servers.

She said hackers clearly were unhappy with disclosure of a vulnerability that they may have been using to hijack corporate Web sites and steal sensitive information. The unknown author of the malicious code included a line saying "Thanks NAI (Network Associates Inc.) for nice bug!" in the script posted on Bugtraq.

(Reuters)