See: http://www.stopthehacker.com/2011/04/20/openx-iframe-malware/
And do this Google search: https://www.google.nl/#q=www%2Fdelivery%2Fajs.php+urlquery
Example: http://www.urlquery.net/report.php?id=592240 MALWARE-OTHER Alureon - Malicious IFRAME load attempt
polonus