Trojan.Zeroaccess.B is a Trojan horse that uses an advanced rootkit to hide itself. It can also create a hidden file system, download more malware, and open a back door on the compromised computer.
The behavior of this threat on 32-bit computers is almost identical to Trojan.Zeroaccess
For more information, please see the following resource:
Click for a more detailed description of Rapid Release and Daily Certified virus definitions.