Resurgence of malicious ACH spam, the digit number changes randomly from email to email.

Keep your anti-virus application up-to-date and if the spam does arrive in the email box don’t click on links within or open any attachment.
The bad guys goal is to install a Zbot variant of a password stealing Trojan that also contains back door functionality. In other words the criminal gains unauthorized access and control of the infected computer.
Reference:
http://garwarner.blogspot.com/2011/05/ach-spammer-switches-to-shortened-urls.html



