American TV host Jay Leno has been named the most dangerous celebrity on the web by BitDefender.

The US Celebrity was mentioned in the subject line of 38,800 spam messages out of a total 25 million analysed by the security firm. Madonna, Cameron Diaz, US President Barack Obama and rock group AC/DC were the next most mentioned celebrities when it came to spam.

However, BitDefender highlighted the fact that celebrities such as Cameron Diaz and Oprah Winfrey that have previously been named in spam attacks are no longer used by cyber criminals. The security firm also revealed that most of the spam messages focused around medicine and the purchasing of pills online.

"Cyber criminals follow the latest trends just as consumers do and they use these and the names of popular celebrities in their campaigns in order to lure people to websites that are full of malicious software (malware)," said Catalin Cosoi, Head of the BitDefender Online Threats Lab.

"As a result, users searching for the latest videos or pictures can instead end up with a host of problems on their computer. We advise all users to have a strong internet security solution in place in order to combat the wide variety of online threats."