It generally takes three to six weeks for a Bing malware removal label to go away, which is a lot longer than it takes for Google, which is days, and can at times be under 24 hours. Regardless, to find out that you've received a malware removal label, only to have to wait weeks for Bing to take it out of their search results can be frustrating. Especially for those who have been hacked or somehow injected with malware. After all, Bing granted users access to webmaster tools long before Google did.
A Bing help thread documents one angry using voicing his concerns:
I have cleaned and secured my site over 4 weeks ago. But BING still shows a malware warning.
I was told that it should go away next time they index the site but i just received email from BING warning me about malware found. This is complete BS!
Perhaps Bing could consider speeding up their process a bit?
In related news, Facebook has been pushing Bing even more as of late, adding a Bing ad to their logout screen.