@Turjan
As to the question about the mod that get's published itself -
It's actually not a virus, or a Trojan, or a crack itself.
It's a mod that adds the ability to switch to Chinese or English and control font size for Chinese\English language for all menu screens.
For Chinese it has it's own dictionary for translations.
That's all it really does per the code, and 90% of the code is just the translation text\dictionary, there does not appear to be anything else nefarious in dll assembly.
Here is the source code extracted via ILSpy:
https://gist.github.com/anonymous/4e9b615e04366fbba1c10eff57387eab
It's uploaded it seems when you start the game on a certain pirated version of the game, but otherwise have a valid steam account.
The code that does that is not part of the ali213_mod_01 that get's uploaded, but is part of some other things they must have modified in the game code they are having people use or they inserted via another mod that doesn't get shared\published. Why the makers of some distribution or crack chose to do that is beyond me, maybe for the lulz or maybe just as really annoying advertisement for their group to make some point about having Chinese translations for the game and being able to change font sizes. IDK seems really stupid to me either way.
One positive thing Paradox\CO could actually take from it though is all the translations, it would give them a start for doing a Simplified Chinese translation.
All we can do is down vote it and report them when they show up I use "Spam\Crack" the latter word being a bit of stretch of course...and then so long as a high number of us do that eventually Steam will get around to removing it, why it takes them so long for each case I don't know and can't excuse, there are ones I marked a week ago still floating out there.
A simple confirmation dialogue would probably work.
Who ever is putting out the pirated distribution would just remove that piece of code (they already clearly made and effort to automate the sharing of a the above mod), and even if they didn't do that, it wouldn't stop old copies already out in the wild. /just saying.
I can't believe steam doesn't have some ability to block based on mod name\title, or even if they don't, don't have a process that can auto scan all published public mods against a list of known bad actor mod titles, running that even just once a week fliping them to private only when found would help, I tend to doubt this is the first time this problem has ever come up.