Chrome's warnings come not from an ability to detect malware, but from Google's knowledge of a given URL having served up infected files in the past.

The warning in this case appears because one of the images in that topic is hosted on dreamworks.ru, probably because that site served up infected files at some point in the past.

I'm not a virus expert, particularly when it comes to viruses within image files, but I tend to think your antivirus software would alert you to any problems as long as it's actively scanning new files as they appear.