Operators of a computer security Web site called AntiOnline last week claimed they had successfully repelled the same type of attack that forced the FBI to shut down its Web site for a week.
AntiOnline (www.antionline.com) is a security Web site frequented by systems administrators and the hacker underground. It was one of many sites targeted in the hacker backlash against the FBI's ongoing sting operation against suspected computer crackers.
But unlike the FBI site, which only recently installed a dedicated firewall, AntiOnline was able to fend off a deadly, denial-of-service attack that has become the scourge of commercial Web sites. Denial-of-service attacks bombard routers, T1 or T3 lines with data packets that prevent users from accessing the site.
Rusty Carpenter, a spokesperson for IBM Global Services, which hosts the FBI Web site, said such an attack was launched against the agency May 26 and lasted several days. After asking the FBI to shut down the site, Carpenter said, IBM deployed filters throughout its network to block packet traffic, asked partner MCI WorldCom to set up its own filters and took IBM's entire network down to purge corrupt packets and take the FBI server offline.
"Never in the years that I've been here has [IBM] experienced an attack this massive," Carpenter said. He said the FBI site would be back online next week with its own dedicated firewall.
Network managers at AntiOnline fought the denial-of-service attack by spreading the rogue packets among various devices, which limited outage time to 3 hours, 45 minutes.
Site founder John Vranesevich said 25 per cent of the incoming packets were blocked at the router with a Cisco Systems IOS Enterprise Plus TCP/IP intercept system. About half the packets were let back into the network but were disabled by an Internet Security Systems RealSecure network monitoring station. The rest of the packets rammed the AntiOnline servers.
Although the FBI attack involved 10 times as many packets, Vranesevich said, his site was able to fight back with only modest equipment. "It's a matter of balancing resources," he said.