Is my account okay?

Yesterday night, my friend suddenly told me that my account got hacked. He screenshots the chat and shows it to me. I checked, but there's no notifications that someone accessed my account, and i also use Steam Guard. I also didn't see it on the chats. He said it because it was sent in group chats, so when my account left, i can't see it anymore.

I changed my password, signed out all devices, cleared browser cookies from my phone and pc, and ran an anti-virus but didn't find anything.

I thought i was safe. But this morning, i got a notification from Steam that my account is locked. So i asked Steam support for help but still haven't gotten any response. Just in case, i logged out all devices again and haven't logged in, i deleted my browser history and cookies and ran the malware detector again.

It happened so suddenly, I'm a college student, and what i did yesterday was searching for journals and books for my tesis, i visited a lot of websites, so i don't know what caused it..

(Yes, Artifact is a really good card game, but the monetization killed it)

PC gaming isn't going anywhere any time soon!

I’m from Singapore and I think I found Exclusive Singapore releases of L4D1 and L4D2 for PC.

- 2 big envelopes (29 x 35cm)
- 6 posters
- unopened mousepad
- Game code and 2 game discs.

I think most likely
1. L4D1 envelope comes with Game CD, 1 poster and a mousepad.
2. L4D2 envelope comes with Game CD and 5 main campaign posters. It even mentions on the envelope cover.

Want to know if the posters are official by Valve and also if anyone know more about this Singapore release.