Hackers are targetting web users booking holidays online in a bid to distribute malware, says McAfee.
According to the security company's 'February Spam Report', internet users are getting emails that claim to be confirmation for an e-ticket for a flight or holiday that has been booked online. The emails contain a Zip file attchment, which claims to be a credit card authorisation form.
However, opening this attchment ensures a PC becomes infected with the Zbot Trojan that will attempt to steal sensitive personal data such as passwords and log-ins to everything from online bank account to social-networking profiles on sites such as Facebook.
The report also revealed that China has overtaken the US as the country respopnsible for most of the world's spam and Windows Live is being used to host websites offering Viagra and other drugs for sale.
"Although Chinese computers aren't being used for spam they way they were last year, we're seeing a resurgence which is now putting them in the lead, ahead of the US. Also, although these zombie computers aren't being used for spam, you have to wonder if they're being used for another purpose," said Jeff Green, senior vice president of McAfee Avert Labs.