That really sucks. Everyone needs to start taking their local security very seriously. Please stop downloading clients from unreputable sources. Every client you download from someone that is not trusted is just asking for this to happen. There are a lot of smart people here and, unfortunately, some of them use their knowledge maliciously. These people can put anything they want into the client, knowing people will blindly download it. Please...I feel for your loss, but everyone has to be very careful and extremely diligent on securing your personal wealth. Don't rely on anything except your own judgement. This is not the first time a client has allowed access via TeamViewer, and unfortunately, I'm sure it won't be the last as long as people keep jumping the gun and downloading garbage

I very highly suggest an immediate backing up of important data, reformat, and starting your OS from scratch, or this will continue to happen