IT security experts have warned computer users to be wary of an email claiming to come from a dying KGB agent, offering to pass on secrets of the John F Kennedy assassination.

The email's author, who claims to be suffering from a terminal disease, says he has access to declassified CIA documents, files from the former KGB, and interviews with key people that have never before been made public. In the email, which has been spammed out to internet users across the world, the scammer tells people that the information could help the recipient become famous.

Part of the email reads: 'You can talk about it with your friends and neighbors [sic]. You can write your own shocking book that will have success and bring you fame. You can call in to radio talk shows. You can raise the issues. You can demand answers – not in 50 years or 100 years, but right now, in our lifetime.'

"There is a conspiracy at work here, but it's not about whether someone was lurking on a grassy knoll in Dallas on 22 November 1963," said Graham Cluley, senior technology consultant for Sophos.

"Internet criminals are conspiring to steal sensitive information and raid the bank accounts of unsuspecting internet users. If everyone showed the same scepticism to unsolicited emails, as some do to the official investigations into the Kennedy assassination, then maybe less people would end up the victims of a scam."

This email con-trick is a variant of many existing 419 email scams, which are named after the relevant section of the Nigerian penal code where many of them originated, and are unsolicited emails where the author offers a large amount of money. Once a victim has been drawn in, requests are made from the fraudster for private information, which may lead to requests for money, stolen identities, and financial theft.