Maybe this will help,
1) Reboot the PC in safe mode with networking
2) Turn system restore off by right clicking on my computer icon. Then go to properties, click on System restore and check box to disable it.
3) Now do a virus scan.
You could also delete it manually, here is some valuable information.
"When the browser runs an applet, the JRE stores all the downloaded files into its cache directory for better performance. We have received reports of the following malicious applets in the cache directory:
Trojan.ByteVerify
VerifierBug.class
Java.JJBlack worm
Java.Shinwow trojan
However, in this instance, storing these applets in the cache directory can not cause any harm to your computer because they are designed to exploit a vulnerability in the Microsoft VM, not the Sun JVM.
SOLUTION
If you find one of these malicious applets on your computer, please use an anti-virus program to delete the applet, or you can clean the cache directory manually.
Here are the instructions on how to manually remove these malicious applets from the JRE cache directory:
From the Start button, click Settings