Slammer Source Code Provides Clues

By Dennis Fisher  |  Posted 2003-01-27

Slammer Source Code Provides Clues

As corporate IT departments go about the business of cleaning up their networks, there are strong indications that the SQL Slammer worm that brought down portions of the Internet over the weekend is based on the work of an obscure Chinese cracking group.

Signatures within the worms source code indicate that a group known as the Honker Union of China—also known as the Hacker Union of China—may be responsible for writing the code, according to security experts who have analyzed the code. However, experts caution that although they are certain of the codes origins, someone else may have actually loosed the worm on the Internet.

"Were 100 percent certain this was based on the CNHonker code," said Chris Rouland, director of the X-Force research team at Internet Security Systems Inc., in Atlanta. "But that doesnt mean they released it."

Although the Honker Union has not yet claimed responsibility for the worm, it has posted on its Web site in the past several versions of an exploit for the vulnerability used by Slammer. The group has been quite active in pro-Chinese and anti-American hacking activity in the past and was involved in a U.S.-Chinese cyber-skirmish that erupted in early 2001.

The worm did most of its damage in Asia, particularly South Korea, which was effectively taken off the Internet for several hours Saturday. And some experts have pointed out that the Slammer worm was released on the anniversary of a major offensive in the Korean War that began pushing back Communist Chinese forces that had penetrated South Korea.

Despite the possible political motivations behind the worms release, White House security officials downplayed the idea that this was an act of terrorism.

"Wed rather characterize terrorism as something that physically kills people," said Marcus Sachs, director of communications infrastructure protection in the Office of Cyberspace Security in Washington. "There was no lasting damage done to the infrastructure. Wed like to see the term cyber-terror dropped."

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The worm, known variously as Slammer and Sapphire, hit the Internet around 12:30 a.m. Eastern on Saturday and began spreading quickly. Within the first hour, it had infected more than 50,000 machines, Rouland said. It continued to spread throughout the day Saturday and has now found its way into more than 200,000 machines, experts say. Its infection rate was much faster than the Code Red worm of 2001, even though there are far fewer SQL servers on the Internet than there are Web servers running the Microsoft Corp. IIS software that Code Red attacked.

But, while Code Red continued to spread for several days, Slammer was contained relatively quickly. The shorter life-cycle is due to several factors, but much of it has to do with quick reactions from ISPs and large network operators who all agreed to block traffic on port 1434, which is the port Slammer uses to infect machines. This kind of wholesale filtering is virtually unheard of and would not have been possible with Code Red. Also, government agencies reacted much more quickly to Slammer than they did to previous attacks, thanks mainly to experience and help from private-sector security firms.

"There was quite a bit of activity going on here," said Sachs. "We first saw it, I think at the [National Communications System] at about 1 a.m., and by 3 a.m. or 4 a.m. everyone who needed to know was out of bed and notified."

Others agreed that the cooperation among the various ISACs, government agencies and private firms was key to the worms containment.

"I was the first one to call the [National Infrastrucutre Protection Center] and that was at about 3:45 a.m., and we had a pretty good handle on the analysis by then," said Pete Allor, director of operations for the Information Technology Information Sharing and Access Center and manager of the threat intelligence service at ISS. "We had the packet captures early, and the analysis was pretty straightforward. We talked to the Financial Services ISAC, [and] worked closely with the telecom folks, all of them."

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