The emails direct users to a website where a file containing photographs of the "suicide" can be downloaded, but in reality, it contains a Trojan horse which can allow hackers to gain remote control of infected computers.

"Computer users who fall for the bin Ladin hoax may be hit by a Trojan horse," the anti-virus firm Sophos warned on Friday, naming the new scheme the Hackarmy Trojan horse.

"Thousands of messages have been posted on to internet message boards and usenet newsgroups claiming that journalists from CNN found the al-Qaida leader's hanged body earlier this year," the security firm said.

"Hackers and virus writers will try all kinds of tricks to entice people into downloading their malicious code," said Graham Cluley, senior technology consultant for Sophos.

"It seems this time that the hacker has focused on the public's morbid curiosity and appetite for news on the war against terror," he said.