I too am getting this problems and it seems to be trying to access a site named ploskinis.com, which is the same ip as listed above. It appears to inject a javascript url to that domain but I see it only in the specific instance noted below.
For me it is only triggered when I search for a forum post and click from there. For example:
I clicked this article from the front page:
http://www.gamedev.net/page/resources/_/technical/game-programming/anatomy-of-an-idle-game-a-starters-guide-to-angularjs-r3767
No warning. After searching the article through the google search in the top right I am taken to the exact same link but javascript has been inserted into the web page. Reloading the searched link will always trigger it. However, reloading the link not searched appears to never trigger it.
Here is the link from the front page, no search:
http://oi57.tinypic.com/6tpseg.jpg
Here is the link from the search, with javascript inserted:
http://oi57.tinypic.com/2n71rg2.jpg
Probably worth noting, I ONLY saw the warning when I viewed the post in the exact same tab that I was searching in. If I copy and paste the URL to a new tab the javascript I noted above is indeed absent. I see it only when using the search function and date doesn't matter. I tried this one from 2014, and tried another article from 1999.
Sorry for the large links, I thought there was a way to shorten them but I must have forgotten. I hope that helps!
Edit:
After testing the same idea of it being linked to the search I tried every article on the front page with the same results. I even tried it with this post and I can indeed confirm for me the insertion only occurs when using the search.