In all three files it’s the same virus: Win32:Aris

2. What sensitivity did you use for the scan? Thorough?
Yes - Thorough
3. Are the files huge? Could you send them for analysis? virus@avast.com
The files are fairly large, between 30 and 60 MB each. I can send you the smallest one, as long as you don't mind such a large email attachment. I could also make it available via FTP. I could probably reduce the file size significantly if I compress it, but I don't know if that might potentially be a problem (given that they are reportedly 'infected'). Please advise.

I’m interested to know that it might actually be possible for a virus to exist within an image format. However - if this is the case I wonder where the virus might have originated. I created these files based on source files from a client, but a thorough scan of my system didn’t identify any other infected files (including the source of these images).