I have rh7.1. How would I know if my computer has been hacked into. And is there some basic security precations I could take.

'Linux hackers Guide' here you can learn how to hack and so how to avoid hacking to your maschine.

The signs of intrusion would depend on just how your system got hacked. Missing files, altered permissions, mysterious user accounts, and unnecessary processes running are a few things that should raise a red flag. You can check the log files in /var/log for suspicious activity, but a good hacker will try to cover their tracks, so you can't trust the log files entirely. Read the online security and administration guides at http://www.linuxdoc.org/guides.html. Standard Linux installs often leave security holes, so if you've got an always-on Internet connection such as cable or DSL, you might want to look into a dedicated router/firewall from someone like Linksys. It will provide an extra layer of protection while you're learning how to secure your system.

I am taking a class on Linux. They gave us this box and they told us to back it up and do a clean Linux install but they won't tell us the root pw. We hear rumors that there is a tool you can use to hack it if you have physical access. (We do.) We have been led to suspect that there may be something of value planted on the HD so we really want to get in and back it up before we wipe it. Or can you back up a HD on a local network without knowing the pw? We are just getting started. We know we have a lot to learn and we know we need to read books and manuals. what we are looking for here is very specific info. Thanks