DoubleClick and Zedo, two of the worlds largest ad networks, were serving online ads that could install Zemot, a piece of malware that connects to remote servers and installs even more malicious software. The attack works by directing unsuspecting users to websites that host an exploit kit called Nuclear, which runs on older versions of Internet Explorer browser or Adobe Systems Flash. DoubleClick, owned by Google, immediately severed its connection to Zedo to stop the malware from spreading.”]