Phantomthe first one says trade offer cancelled though, not that it was declined by the other person. If you didn't do it doesn't it mean the person had access to your account and cancelled without you knowing?
I think this is correct as I'm putting more pieces together. I never entered any account details outside steam but I think this is the case
I'm editing out the main post since I'm not sure how to delete, seems like it was just a compromised account