Chrome Extensions Cookies Hack

“Apart from offering the intended functionality, the extensions also track the user’s browsing activity. Every website visited is sent to servers owned by the extension creator. They do this so that they can insert code into eCommerce websites being visited. This action modifies the cookies on the site so that the extension authors receive affiliate payment for any items purchased. ”

Source : Malicious Cookie Stuffing Chrome Extensions with 1.4 Million Users | McAfee Blog