the .tar.gz is a compressed file, in order for any anti-virus program to check it, it has to Unpack (upn) it and as far as I am aware it does this in avast4 which I believe I mentioned before.

If it keeps coming back, dont just temp disable System Restore using msconfig (don’t see how you did that) anything that you delete from the system folders will I believe be regenerated at re-boot.

Any changes you make in msconfig, don’t take effect until after a re-boot and I don’t believe that system restore was properly disabled.

Go the distance and do it properly and then re-boot. Scan, resolve the problem, re-boot, check for infection and enable system restore once you are clear and re-boot.

Any backup that you do prior to cleaning could be leaving yourself vulnerable to reinfection if you use the backup.