A variant of the Zeus Trojan has been discovered posing as a message from the Royal Mail service in the UK, according to an article on The Register. The attachment, which is a PDF file (one of the more widely used platforms to deliver malware), contains an executable file that has been linked to a command server in China.
According to Websense Security Labs “Zbot (also known as Zeus) is an information stealing trojan (infostealer) collecting confidential data from each infected computer. The main vector for spreading Zbot is a spam campaign where recipients are tricked into opening infected attachments on their computer.”
The message purporting to be from the mail service claims that the postman missed the recipient and that the user should download and view the “invoice” and contact Royal Mail with any questions.
You can read more about the Zeus Trojan here