AV Does Not Scan AVI's!

I have tried right clicking on an AVI file or a folder that contains an AVI file but CIS AV does not scan it. Why?

By default CIS is set not to scan files bigger than 20 MB. You will have to change that. When in the main screen choose Antivirus → Scanner settings. Now change the setting for size in Real time , manual and scheduled scans.

How big is the file?..the default file size setting is 20MB…so anything bigger than 20MB will not scan.
To check/change file size scanning open CIS…click on Antivirus tab…click on Scanner settings…click on manual scanning tab and increase the size accordingly and apply.
I hope this helps ;D

Great minds think alike EricJH ;D

Thanks, I’ll make that change. Didn’t think of looking there.

Made the change and still won’t scan.

?? are you sure the file isn’t corrupted in some way?..can you try to scan another file of similar size?
Also are you sure you changed the manual scan setting size and not the real time setting.

Somethings wrong. Seems to ignore any setting and scan only files smaller than 20MB.

I just altered my settings in manual scan and tried a big avi file and it scanned it no probs.
Other than asking you to double check you have changed the the size in the MANUAL SCANNING tab snd NOT the real time scanning tab then I am out of ideas.

Yes, MANUAL is changed and it will not scan any AVI.

Did some more testing and it does scan files larger than 20MB but will not scan any AVI’s, most of which are in the 700-800Mb range.

Lashf, You won’t get a virus that’s 700-800mb. Thats why comodo only scans files under 20mb which is both pratical\effective and secure.

You’re probably right; a virus won’t be that large. However, a virus can be attached to a file of any size. Right?

that’s correct, Such as a large .ZIP file that contains the virus inside. But it can’t cause any threat until it’s extracted and executed.

I have seen this come up a few times and read a great amount of debate on the issue.

AFIK the often suggested file size setting/changing isn’t the issue.

Comodo (again AFAIK) has made the conscious decision to not scan AVI’s and any other
number of certain file types.
As they don’t fall under the category of “infectable executable”.
A decision with which I agree, my virus defs would be outdated before I ever completed
a scan for one reason.

So yes you are correct malicious code could be contained in any file size.
I don’t believe you can bury a valid executible in an image/video that would work
without wrecking the image/video.

To clarify some. If you double click on or app calls an executible your OS knows how to handle it
commands get carried out etc.
If you double click the AVI your OS purely by association executes the associated player or
viewer. Your player/viewer doesn’t know how to interpret executable code.
So in a picture if it would even view, there would be blank spots or some sort of weirdness.

The closest I have seen to a malicious program in a video is the scam video that exploits
Active X in WMP IIRC so that when you open the video you get a message that you need
to download a “special” Codec to view this video, BINGO there’s your viral executible.

Having said all that the real time scanning covers all reads and writes regardless so you
are covered anyway.
Make sense?

many audio/video files (from e.g. p2p) also contain a hidden file extension which opens your browser to malicious sites/downloads when ‘played’.

:-TU .FaZio93.

I forgot to mention that dirty old hidden file extension trick.
CIS should get those though.

They are files that are embedded within the media file.

oh yes. CIS gets them before they’re even downloaded. :wink:

They can definitely add url’s to videos that then will open your browser to go to a web site. So I assume that mechanism could also be used to start code to exploit vulnerabilities in media players? I am not an expert here.

All the more reason to allow the user to scan any file he wants.