Sites claiming President-Elect Barack Obama will refuse to take the oath of office Tuesday are serving up attack code believed to be programmed by the same hackers responsible for the notorious Storm bot Trojan, researchers said this weekend.

According to researchers at several security companies, including F-Secure, MX Logic and Trend Micro, spam campaigns are in gear that try to trick users into visiting malicious websites hosting variations of "Waledec," the Trojan horse thought to be the successor to Storm.

Sam Masiello, vice president of information security at MX Logic, was one of the first to call attention to the attacks, which begin with one-line spam messages such as "Haven't you heard latest news about our president-elect?", "Barack Obama abandoned sinking ship," and "Obama doesn't wany [sic] anymore to be a president."

The links in those messages lead to a legitimate-looking site that resembles the real Obama-Biden campaign site. The fake site contains both bogus and real news stories. At the top of the page is a story with the headline "Barack Obama has refused to be a president," that includes text which reads, "On the

Eve of Inauguration Day President-elect Barack Obama made statement. He declared that he is definitely NOT ready for this position."

Clicking on a link to read more of the story triggers a download of an executable file that is in fact a variant of the relatively-new Waledec, according to researchers at Trend Micro and F-Secure.

Waledec has been linked to 2008's Storm by researchers including Joe Stewart, director of research at Atlanta-based SecureWorks and one of the leading experts on botnets. Last week, Stewart released a new census of the world's biggest botnets, and put Waledec in the number 9 spot with an estimated 10,000 hijacked Windows PCs under its control.

Waledec, said Stewart, shows all the signs of having been written by the same group, if not the same person, that crafted Storm. "It's so similar that it's unlikely that it's a different group," he said last week, citing the similarity of the messages that start the attacks, as well as the malware's coding.

The Waledec bot first began infecting systems just before Christmas, and used phony holiday greetings and e-cards - a tactic also employed by Storm during 2008 - as bait.

"As is often the case with these new outbreaks, [antivirus] detection is scarce so be aware of this new tactic," Masiello said in an entry to the MX Logic security blog Friday evening. The company was tracking approximately 4,000 fake Obama emails per hour on Saturday.