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 Corp., MX Logic Inc. and Trend Micro Inc., spam campaigns are in gear that try to trick users into visiting malicious Web sites hosting variations of "Waledec," the Trojan horse thought to be the successor to Storm.