The email actually contains a malicious attachment with the file name Paymentcert.jar, detected as Trojan.Maljava. If the Trojan is executed, it will drop JRAT, detected as Backdoor.Jeetrat, on the compromised computer. The RAT not only affects Windows PCs, but also Linux, Mac OSX, FreeBSD, OpenBSD, and Solaris computers.
Read more here – http://www.symantec.com/connect/blogs/jrat-targets-uk-and-uae-payment-certificates-spam-campaign