Why Does Google Consider Some Images Malicious?

The other day I received an email from a webmaster whose site was blacklisted by Google. In Webmaster Tools, he found the following example of a malicious code detected on his site (domain changed):

<img src="http://example .net/images/logos/rssicon.png" />

So why did Google think this image tag was malicious? Can images be malicious? After all they are not scripts, iframes or embedded executable objects that that hackers use to attack web surfers.
Continue »»