How do you tell what Bing is detecting as malware on a page?

Question

Bing Webmaster Tools started flagging some of my pages as infected with malware. Despite my best efforts, I have been unable to figure out what the problem might be. The "help" message about the malware is:

Malware Network Reference

Reference to known malware distribution network detected. This could be via inclusion of an iframe or frame tag, an embedded object, or a script tag.

So far I have:

• Verified that the source code for the website is unchanged (I verified that it matches what is checked into git, and that there is nothing weird in the commit history)
• I fetched the page as Bingbot and compared it to a version that I downloaded using another user agent to make sure that there isn't something serving Bing an altered page
• I grepped the page source for case insensitive script, frame, object, and embed to make sure that I recognize all the code.
• I grepped the page source for case insensitive https?:// to make sure I recognize all the links

What else should I be looking for?

The only scripts that are in the page are either inline scripts that I wrote myself, or tags that include AdSense ads via DFP. Could the ads be inserting content that Bingbot is complaining about?

Is there any way to get further information from Bing? I was unable to find anything further that might be helpful in their webmaster tools. I couldn't find that they said anything about which specific malware, or what code snippets from my site might be problematic.

Answer 1

Bing has now deleted its malware warnings from Bing Webmaster Tools. I think at this point it must have been a false positive.

I never did find any way to dig into what the issue was. Bing does not appear to publish any in depth analysis of what malware it actually found or what triggered their report.