Success Ratio: Clean & Delete

We all know what 'clean' and 'delete' mean in the terminology of antivirus sphere. My question is, how well is the chance for an antivirus program to actually succeed in cleaning and restoring the functionality of an infected file, rather than simply deleting it?

Assume that an executable is infected and partially overwritten by malicious codes, but it still functions untouched, what are the odds for an AV to successfully clean it without inflicting further damages to itself and making it unrecoverable?

Thanks for your comments and insightful remarks.

 

It seems there's no definite answer to this question yet? Any comments from a technical perspective, say approx. 20% malwares can be cleaned/restored? Thanks.

 

If it is a virus that infects files and if the AV product knows a cleaning algorythm for it , then the AV can remove the infected part of the infected file and the file will work . I have had two or three cases with NOD32 when there is a virus infecting files and it was successful cleaning . I don't know of any statistics about successful rate

However , there is a virus -> W32/Parite.B , for which it is much better to have proactive protection because it must be caught early to save the files.When run , it slowly infects all EXE and SCF and destroys them by overwriting them completely.

 

You usually only need to clean viruses, and since they are a pretty dead breed by now it shouldn't be anything you need to worry about.
Todays threats are all worms, trojans, rootkits etc. Of course there are new viruses appearing but it's been a long time since I've seen one.

Well that's my view on the matter anyway.

 

Thanks. I just did a little digging and came to know that I was actually referring to a particular type of virus known as parasitic viruse or file virus. That cleared things up for me. Thank again.

 

Thank You