Haxdoor is one of the most popular and dangerous Windows based rootkits. Users should continue to be cautious with all suspicious email messages.

Haxdoor.CP - Spammed email with Rootkit
http://www.incidents.org/diary.php?storyid=1508
http://secunia.com/virus_information/30929/haxdoor-cp/
http://www.sophos.com/security/analyses/trojhaxdoorcp.html

QUOTE: Troj/Haxdoor-CP is a Trojan for the Windows platform. Troj/Haxdoor-CP runs continuously in the background, providing a backdoor server which allows a remote intruder to gain access and control over the computer. Troj/Haxdoor-CP includes functionality to: - stealth its files, processes, registry entries and services - prevent itself being terminated...

Email to avoid:

Subject line:     Confirmation for Order WC2905036
Message text:  Dear Sir/Madam, Thank you for shopping with our internet shop. Your order, WC2905036, has been received. Summary of your order you can see in the attachment file.