What antivirus do you use? A screenshot of the error would help.

I restarted after making it not start on startup and I can run tf2 fine now. And it doesn't really matter which anti virus I am using, it downloaded an .exe into my roaming folder and it obviously wasn't something good.

Do you have ads on TF2OP?

I have an ad blocker.

It could be the BuySellAds ad zone. Try using NoScript when browsing websites. :)

Not really sure why that would be downloading .exe that are asking to use my private networks and which my anti virus is considering a threat.

It was the best-case scenario if TF2OP were to be actually sending you viruses, otherwise, we've got someone who beat me to an exploit

Originally posted by Zemnmez:

It was the best-case scenario if TF2OP were to be actually sending you viruses, otherwise, we've got someone who beat me to an exploit

Or that someone had a link to a marked virus site on their trade.

Originally posted by Regen #01101011:

Originally posted by Zemnmez:

It was the best-case scenario if TF2OP were to be actually sending you viruses, otherwise, we've got someone who beat me to an exploit

Or that someone had a link to a marked virus site on their trade.

Oh, do antiviruses detect that these days?

I'm behind with the times...

Maybe it hasn't been very clear... :I There was an actual .exe, downloaded from the site without me clicking any links. It was asking to use my private networks and was running in processes when I checked task manager.

Originally posted by ChimpBalls™:

There was an actual .exe, downloaded from the site without me clicking any links. It was asking to use my private networks and was running in processes when I checked task manager.

Hard to understand what exactly happened. A little more info about the circumstances might help to discover what was going on.

How did you know the .exe came from OP? Did you witness the download, or do you have any idea how that happened? What page did you look at? What browser are you using and was it up-to-date. Do you use any 3rd party OP plugins, like the toolbox?
What are the "strange updates" you mentioned. Do you know what was updated?
Is the problem gone now? Do you know which virus it was? That should be visible in some kind of log you AV Software keeps.

A .exe called "couv" was downloaded. I had OP minimized and when I opened it and went to my trades, a program called "couv" which was downloaded a minute before according to the log, was asking to use my private networks. The only plugin I have is an ad blocker. My browser is up to date. And the update from steam was just some new thing I hadn't seen before and was apparently just a coincidence.

May I ask what log showed the time the .exe was downloaded. Was is the browser and looked like a "normal" download like if you had clicked it yourself?

No. I located the folder it was downloaded to and it said it was created at whatever time it was.

My guess would be that the .exe has nothing to do with OP directly, got into your system some other way and that it was just a coincidence that the virus alert popped up when you activated your browser with OP being the site open.
The virus may have been dormant in your system for some time. Without detailed analysis of your computer it is impossible to tell what really happened.