Can avast! Antivirus heal a file from a infect virus? Or will it only detect a virus and have to delete the file or put it into the chest?
Hi MFB and welcome
Can avast! Antivirus heal a file from a infect virus?Please have a look at Avast! VRDB, the answer is here ;)
There is an option repair. 
Only true virus infection can be repaired, e.g. when a virus infects a file it adds a small part to it, provided that file is one that avast’s VRDB would monitor (such as system files, .exe or dlls, etc.) and you have run the VRDB, then it may be possible to repair the file to its uninfected state.
However, for the most part so called viruses, trojans (adware/spyware/malware, etc.) can’t be repaired because the complete content of the file is malicious. This leaves you with the safest option, move to the chest and the final option of deletion. When a file is in the chest it can’t do any harm and you can investigate the infected warning.