Think I'm having the same issues as memesweeper. Only seems to occur on iOS on Safari (iOS 10.0.2), but not on my MacBook. When visiting Flyertalk forums (and also PPRUNE, also Internet Bulletin Boards occasionally though with nothing like the same frequency as on Flyertalk) I regularly get an App Store popup like below.



If I remove the data:text/html;base64, and then run the remainder through a base64 decoder it does generate html, and I can pass this to anyone that needs it, but don't want to post it generally as it does include some personal information.

This seems to occur when there is a Monster Legends advert at the top of the page, but this may be unrelated.

Having cleared all website data from my phone this continues to occur, and still occurs following a full reset to factory settings so I don't beleive this is related to malware on my phone. I presume it is a rogue advertiser using a rather sketchy JavaScript command to try to force me through to the App Store.

Is this occurring for anyone else, and do I need to do anything else to bring it to the attention of Internet Bulletin Boards or do they read new posts in this forum?

Many thanks,
Hodders