I think the term you are looking for is crackers. Your Ubuntu Linux only exists in great part because of "hackers". That said, it is probably a good idea now to change your password on any other service that might have that same pw.

Probably a good idea to enable 2FA with your Steam account. I also don't save payment details just in case something like this happens. Plus I make fewer impulse purchases when I have to type in my payment details every time I want to buy something.

While I agree it sucks when your account gets stolen, you've got to remember that sometimes if you get an account stolen it usually means you had a weakness in your own security setup.

I'm not talking about vulnerabilities, but rather passwords etc.

Few things to take note of:
* New Passwords
First and foremost make sure they are secure by having a high entropy count. The higher the entropy the harder it is to brute force the password.

* Old/Used Passwords
Never use the same password twice. Never. Using the same password twice means that if another service gets cracked then that gives the crackers access to any other account you have with that password.

* Password Management
I recommend you use an application like KeePassXC to manage your passwords rather than firefox etc.

* Two Factor Authentication
Where available enable it.

* Monitor all services you use
If you find out a service you use has had a data leak immediately check to see which email and password combo you used to use on that service. Ensure those credentials cannot be used anywhere else and change the credentials you use on that service.

* Ensure your own computer is up to date and secure
Sometimes it can be your PC that is cracked first and from that crack information is taken to get into services you use. Yes, this includes GNU/Linux. While GNU/Linux generally is more secure, it is not a bullet proof vest and you must ensure you keep it up to date and configure it securely. For example, don't leave port 22 open with the default configured OpenSSH enabled on your home PC for no reason.

All in all make sure to protect yourself first, you cannot blame others when you ignore your own security and get stung for it, just sayin'

Quoting: AnxiousInfusionI think the term you are looking for is crackers. Your Ubuntu Linux only exists in great part because of "hackers".

These "hackers" are the hipsters of the software programming community. It's what they call themselves to make their job or hobby sound cooler. Event marketing people obviously love the term, but that's because hipsterism is a job requirement for them.

The rest of us are coders, developers, programmers, nerds or whatever gets the point across. And hacking still means what it meant 30 years ago.

/getoffmylawn

https://stallman.org/articles/on-hacking.html

Quoting: Doc Angelohttps://stallman.org/articles/on-hacking.html

A hack (as a noun) can mean an innovative solution to an every-day problem, but "Playfully doing something difficult, whether useful or not" is not hacking, no matter what Mr. Stallman thinks.

Honestly more curios how the leak happened.
Wonder if they brute forced it or was it a script on a site that was malicious and managed to do it.
Can you remember what you were doing prior ?

EDIT: Notice you dual boot. Could your windows be compromised ?

1. Use a Mobile authentication method with Steam , is a must these days!
Even if someone hacks your email he cant do anything on your steam account without the mobile authentication.

2. You have a permanent/resident virus/trojan called Windows
Windows is a very scary place to use these days. Even if you are only connected to the internet you get attacked.
Watching movies especially wmv files you get infected
Opening files you get infected
installing pirated games/apps you get infected even from trusted sites.

3. if you are still infected , they will get again your new email pass and steam account if they want to do so.

Even though my main job is in the IT industry I have stopped using windows when I saw the mouse moving by itself and some applications opening by themselves and that was before many years ago.
Supposedly I am an expert to these things and such things should never happened to me.
Well I was wrong and the only thing they got from me was my dropbox account which later I found it was filled up with porn pictures. :P

After that incident I wanted a more secure OS so that's why I ended up With Linux.
I feel more secure and so far nothing has been hacked or any information has been leaked from my pc.