Well, I don't have a malware infection on my machine (at least, not as far as I can tell) and this TempImages directory was in my %Localappdata% folder. It appears to have been filled with setup programs for those programs which are packaged with free software.
According to VirusTotal, the Free WAV to MP3 Converter that I was using was packaged with malware. I think the reason I haven't had a problem is because I didn't use the stupid toolbar app that came with it.
Nonetheless, I don't see why we shouldn't include this in the Winapp2.ini file. I've already added it as a custom location in my own installation of CCleaner.