The most popular bait used by spammers is 'Angelina Jolie' – four times as popular as Barack Obama whose name falls behind in second place.

The spam bait list, compiled by Secure Computing in its August threat report, shows that during the past month, 12 million spam messages – from 100,000 unique IP addresses on the first day of outbreak – were sent with Jolie's name in the subject line. Around 2.28 per cent of the total global email volume was found to have text such as “Angelina Jolie naked”.

Dr Sven Krasser, director of data mining research, said: “Spam is the delivery medium of choice for social engineering schemes to create a tempting lure for consumers. One small mistake can be costly. For example, when a mobile worker falls prey, they may unknowingly penetrate and infect the corporate network.

“It is therefore imperative for organisations to secure the paths to the network properly. Especially with the proliferation of blended threats, it is of paramount importance that organisations protect both email and web gateways.”

Other new spam waves include messages that include fake invoices, such as those claiming to be from UPS package tracking, whereby recipients risked downloading the Agent.JEN trojan.

Panda Security, which discovered the UPS-related bug, said the suspicious emails have subject text along the lines of “UPS packet N3621583925”. The messages claim that it was not possible to deliver a postal package and advise recipients to print out a copy of an attached invoice.

The top 10 ranked spam bait names are: 1 – Angelina Jolie; 2 – Barack Obama; 3 – Paris Hilton; 4 – Britney Spears; 5 – Hillary Clinton; 6 – George Bush; 7 – Jessica Simpson; 8 – Osama Bin Laden; 9 – Brad Pitt; 10 – Michael Jackson.