NOTE: the steps below works only if you are on the latest versions of ZA. If you are not, please update.
Try to perform a full Antivirus/Antispyware scan but in SAFE MODE WITH NETWORKING.

1. Disable system restore;
2. Set ZA Antivirus/antispyware to "Ultra Deep Scan" under the advanced options of the ZA antivirus/antispyware tab (scan modes);
3. Reboot in SAFE MODE WITH NETWORKING;
4. Manual run ZA (ZA firewall will be OFF but Antivirus/Antispyware will be functional);
5. Run a full ZA AV/AS scan;
5. Reboot in Normal Mode
6. Set ZA Antivirus/Antispyware back to Normal
7. Ensable System restore

How to start in SAFE MODE WITH NETWORKING
How to disable windows SYSTEM RESTORE

If the above fails try to clean your system with:

1. Download update and scan with MBAM
WARNING: Some malware will block the download of this software, rename the installer to a random name before saving and running
2. Download. update and scan with superantispyware FREE
WARNING: Some malware will block the download of this software, rename the installer to a random name before saving and running
3. Download update and scan with A2 free

Still Problems? Try the bootable CD fromDrWeb

if ALL the above fails please post your Hijackthis log to BleepingComputer or SpywareHammer

Cheers,
Fax