Avira: Scan when Writing Only

I've seen some posts recommending Avira's guard to scan when writing only. Is this sufficient? If I insert a thumbdrive with infected files will I get infected to? Does it stop you when u attempt to execute an infected file that's already on the system?

TIA for the clarifications

 

Similar to Dr Web's "Smart mode" I suspect.
Whereby all files created / written to disc are scanned, BUT existing files can be opened and existing executables run (i.e.: program executables) without scanning.
Hence the rationale for initial running Full System Scan, and possibly every so often.
Saves on resources.
Re: USB. Anything written to HD from USB should be scanned.
(Don't know about Avira, but some AV's implement USB autorun prevention for additional security)

 

This wouldn't cover you in the case where your machine is infected before the pertinent definition update is applied. Am I correct? Not sure if this is a likely scenario.

 

Hi,

It is only applicable (write only) when you are absolutely sure you have a clean PC AND use DefenseWall, GesWall, SandBoxie or something simular. Otherwise read and write is the best option.

Regards Kees

 

A common scenario with write only.
I download a file, Avira scans the file on write to disk and finds nothing.
Next day I execute the file. Bad luck, it's malware which Avira added to their blacklist in the meantime. But it's quiet, because of write only.

Last happened a few days ago, when I was fishing for Winlock. When I grabbed the file Avira didn't detect it, but on the next day it was TR/Dropper.Gen.

Cheers

 

If you were going to pick one or the other, I'd think it would almost make more sense to scan on read only.....

 

Yeah I don't see what you were getting at either...

 

You know the answer, don't you?

Yes, true. But this thread is about 'Avira: Scan when Writing Only' and not about common black-listing problems.

I just wanted to give a hands-on experience for the drawback of the write only setting.
And it doesn't matter if you have downloaded this file a day ago or a month ago.
As long as you don't run an on-demand scan, Malware, which was added to their blacklist in the meantime, will always be executed without detection.

Cheers

 

Thanks guys for the input. Much appreciated!

Yeah my PC is scanned and fully clean (I hope) before I set avira to scan on write only. Also, I usually sandboxie downloaded executables, so I guess I'm somewhat safe.. I'd like my processes light as possible so i'll leave it at scan when write only.

And I guess I'll make an effort to reenable scan on read everytime I use a USB drive.