Solution adblock plus( https://adblockplus.org/ ), The Powder Toy needs ads to run the servers and pay for software that is needed to updated/improve the game. Also I highly dough you get those types on ads since Google ads don't show content like that.
Use WINDOWS DEFENDER
The best out there!
The ads on the banner of this website doesn't matter much. Does not change the appearance of other parts of the page.
Possible cases:
1. Your ISP or the proxy you used adds advertisements (My ISP do!). Check the source code of the page and if there is some kind of advertsisement script (usually at the beginning or the end) or the whole page is in a frame, this is the case. Use/change a proxy server or use HTTPS (TPT doesn't seem to support HTTPS except login page)
(@Simon Please enable TPT in HTTPS, for example, force HTTPS when a 'HTTPS=1' cookie is present)
2.Your computer had some viruses. Use a virus scanner.
Check if the ad source is normal. Mine is http://pastebin.com/7GS1zDHV
You're computer is likely bugged. It isnt a malicious program, apparently, but rather just one that creates ads where ever it can.
Check if you have installed a program that does that ([works on windows 7 idk about the rest]start>control panel>programs>under the programs and features, you will find a text saying Uninstall a programs) but don't uninstall an important program (you can google them to make sure they are important).
See if you have an ad-on that does that (there should be an option to view your ad-ons in your internet browser).
Scan your computer.
If none of that worked, give your computer an expert so that he can fix it for you.
Edit: I misspelled the word "uninstall" :3
ok now what I just posted was ads \o/ hehe
make sure to block it as well XD