Hi utrobin,
what files are being flagged as malicious? If you think those are false positives, please submit a false positive report. We are constantly monitoring this detection and updating it accordingly, so most false positives should be resolved soon. Since this is a generic detection avast! certainly won't be able to repair the infected files, sorry. If you are still seeing this detection even after virus definition update, please post more information about the flagged files (their name, location on hard disk etc.) so we can look at this issue in more detail.
Regards,
Peter Kovac