Are they just an issue with wefwef or trying to use an exploit
Hey, I can tell you want it does. While I don't know if they try to download something too (while it really doesn't look like it), they are trying to steal your browser cookies.
I haven't removed the obfuscation yet as I am literally in bed but I can tell the general idea of the code.
Onload is a html attribute. Html attribute tell your browser more about what the browser should be doing. So basically onload is an instruction to your browser. By posting those comments, they try to run something called cross site scripting. Basically they want to run their code in your browser without them being the website owner. So now we know the intend of the post, let's look into the details.
Onload is an attribute that tells the browser to do something once it is fully loaded.
Fetch is a function that allows your browser to request additional information from the server. Endless scrolling would be done with that.
String.fromcharcode is just there to hide a little bit. Think of it as a fancy way to say a word. they are saying a website to connect to there.
Then document.cookie are your cookies for that website.
The next thing is probably your username or something.
So what does that mean? They try to make your browser execute their code when the website is onloaded. The code sends your cookies and your username(?) To a server. They probably save the username and cookie and try to steal the account later.
You seeing the code is good evidence that your browser hasn't execute the code as the browser didn't understand it as code to be executed but code to display. So you are probably safe and don't need to worry
Edit: ups sorry for not answering the question. I don't know which client they are targeting. They might or might not be targeting wefwef. But they target you, the user, too. And it is probably for Webbrowser users, so chances are wefwef or other web clients.
Edit edit: some people pointed out that it is not the username but basically the admin status of the account.