How to beat Ads and XSS people.

This flash swf, injects javascript into the page in which it is loaded in and performs an XSS to the url hardcoded in the flash file.

Many ad networks that accept flash content do not check for this. 
When you upload the swf file to the ad-network, and when it is served to the user, the user will be XSSed.

This is useful when privacy researchers need to do studies of ad networks.
For example a use case could be to answer questions like:

How many ad networks do not embed content directly into the page and not inside iframes thus enabling us to steal user's session information.