Also known as MIME Sniffing, this is a feature or bug in IE which is the only browser able to dynamically determine the content type of the document it loads. So, in this case, it detects a plain text document with HTML content instead of a an JPG header. And the content of the “JPG” file which is text/html: The URL was reported to Phishtank and CleanMX. The users of Avira Professional and Avira Premium Security Suite are protected if they use the latest Webguard signatures.