Can ico file carry a virus or so?

[huidong]

Avast Web Shield frequently scans various favicon.ico files. I wonder if ico file is a potential threat, i.e. can it carry something malicious at all? If not, I will exclude this type. And I'd also like to know if jpg file can be malicious, since by default, Avast Web Shield excludes gif and png files, but not jpg.
Thank you!

[morno]

how big is the .ico file? yes images can carry viruses, etc.

[DavidR]

Do you mean something like a favicon.ico file ?
The answer for that is also a yes as the file itself can be hacked to do something other than display the favourites icon.

If you mean .ico that you burn to CD/DVD, in the form of an image of a CD/DVD then absolutely, as that is like a huge archive file that could contain anything, just like the original CD/DVD.

[huidong]

Yes favicon.ico from the websites I visit (Since I'm talking about the Web Shield). I did not say .iso, I mean .ico, which I don't think is any sort of CD/DVD image format. Am I correct?
By the way, could you say more about what kind of cracking or infection typically targets icon files, especially favicon.ico for websites? Thank you!

[DavidR]

Yes you will have noticed a lot of detections by the web shield on hacked site, a trick to hack the favicon.ico file as the browser will try and load that into the address bar where the icon goes. So it can be used as a means or running malicious code.