The issue here is a broken functionality that I've reported on before with Google Ads which Bing mirrors: Allowing advertisers to lie about the destination URL of their ads.

Here's a screenshot of the same exploit on Google: https://plus.google.com/u/0/115181074626403443464/posts/fSPm... (The included hijack was blocked as a malicious site on Edge, but wasn't on Chrome.)

Ads should always be forced to display in the URL text the actual URL the ad directs the browser to. Maybe as a side bonus, less tracking URLs will get used to keep it looking cleaner.