I've been hacked :(

I'm ashamed to admit it but one of my machines was hacked. It was a media server running an older linux distro, I more or less forgot that box was still up and running in a house that is up for sale. Last week when I went there to turn up the heat so the pipes wouldn't freeze I noticed I couldn't use the machine to check up on some websites. I figured it had crashed and brought it back down south with me to have a look at what the cause was.

So, the cause was pretty simple, someone managed to get in through my not-so-carefully concealed backdoor, how they managed to crack a 20 digit root pw is something I'll never know.

Lesson learned, even old and rarely used systems need to be kept secure and up-to-date, the box was sitting on a 10 Mbit adsl line, most likely it was used for some not so nice purposes.