Open http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js . It will take you to http://download.cloudantivirus.com/eng/malicious/?id=antiphishing-vmninternethelper1_1dn&url=ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js . Check the "I understand that visiting the page could infect my computer." check box and click Continue hyper link. After that if you do CTRL + F5 on stackoverflow page, it should not show the error. Thanks.
Ravi