I’ve been looking into this a bit more and have a few observations,
We only use the major ad networks Google, Microsoft, AOL and Switch. They are very conscious of ad malware and I would be surprised if they were distributing this code.
We have hundreds of thousands of Android users on the site and it is the same few who report recurring problems.
I use the site on my Android Nexus 7 and HTC One S regularly and have never encountered a problem.
All this leads me to believe the problem may be with the users devices. Google does not vet the quality of apps distributed via the Google Play store so the odds are that some of our users may have installed a dodgy app at some stage. Equally, Android devices are vulnerable to viruses and other malware. It is recommended that you should run anti virus package on your device.
Ultimately as I have been unable to replicate the problem I can’t see how I can help further. If you have any further information that would help me identify the cause of the problem I would be happy to investigate further.
We are keeping the ad networks informed of the concerns in case they are the source..