Last week, Bing had an unusual bug, a bug with its cache page results. The Bing cache was showing not just the cache page they had of your site, but also showed content from non-related sites below or above your page.
Bing fixed the issue about 24-hours after it was reported to them and said it was a bug, not a hack. Here is Bing confirming the issue:
Here is a screen shot of what my Bing cache result looked like that day, notice the content on the footer:
This is all resolved now but Bing really didn’t say what the issue was. It was not a “hack” they told me, but rather just a “bug.”
Forum discussion at Twitter.