What is it?
Backdoor.OptixPro.12 Trojan kazza.exe

What does it do?
Backdoor.OptixPro.12.c, a variant of the Backdoor.OptixPro.12 Trojan Horse, can provide its creator unauthorized access to an infected computer. By default, this Trojan opens port 3410 on a compromised computer. The existence of the file Kazza.exe is an indication of a possible infection.

Removal:
Symantec has the full dirt (HERE)