The hacked web pages appear to have been infected with scripts, which not only install malware on users' systems, but also prevent browsers like Firefox and Google Chrome, which use Google's Safe Browsing API, from issuing an alert when users try to access the page. When Google's search bot encounters such a specially crafted page, the page responds by simply returning harmless code. This camouflage strategy takes advantage of the browser switch normally used by developers to return browser specific code to suit functional variations in different browser, such as Internet Explorer and Firefox.
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