3 times in the last week while looking at this forum on my Android phone an HTC one M7 there have been new windows opened and buttons disabled on my phone by this virus/scam to prevent me from closing it.

Screen grabs taken this morning when it happened again:

the first event:


then:



then:


-

The back button on my phone is disabled by this, the only way out is to power down my phone and hope it has not been infected by this.

I am now wary of using my phone as it is used for online banking and paypal payments and now I may have a virus because of proboards.

I don't mind adverts but this is just a scam attempt as there is no way anyone will send me a free iphone 7

This needs resolving ASAP.