My friend received iMessage in nonsensical Chinese on his iPhone from me. I checked my iMessage in my MacBook Air and I see the same but I never sent it out. Should my MacBook be beached?

My friend asked me that I ever iMessage him in nonsensical Chinese. But I never sent those iMessages out to his iPhone. I checked my iMessage app in my MacBook Air and indeed I do see those messages but I never did. So I logged into my Apple ID site then I see 2 other unknown devices listed I am not signed in or i have never signed in before. Does that mean my MacBook Air is breached or hacked? Does anyone know "pensirot.com"? If my computer is embedded with malware, that's the only site I can suspect doing this.