I have a Ubuntu 14.10 machine and I would like to check if my security is OK. I doubt that some one accessed my machine from internet and remotely controlled it. so what are the suitable tools I need to use to see if that really had happen and what are the logs related to this issue I can check for history ?
It is a very vague question because Ubuntu Security is pretty good out of the box, and if I would have hacked your computer, you would not be able to actually check that you were hacked as I would have installed a rootkit, and the only way to get me out of your computer would be by restoring a back-up since before you were hacked…
The best way not to get hacked is to prevent it.
- Turn off all hardware you don't need in the BIOS (this includes: microphones & speakers as they have been shown in the past to be used as communication channels once the PC was hacked, printer ports, USB ports, WiFi, etc)
- Don't install Ubuntu in an Internet café, but at a secure Internet behind a NAT router.
- Install RKHunter just after installing from DVD
- Black-list all hardware you don't need and that cannot be disabled in the BIOS
- Secure your system
- Always install all updates
- Don't let anyone physically touch your computer
- Use encrypted communications
- Install as little software as needed (and uninstall software you don't use any more)
- Don't install software known to track you (flash, silverlight)
- Use Firefox with the noscript and modify headers plugins
- Disable all cookies. Only allow cookies per site and only for the session.
- Make system back-ups so you can roll back to previous versions
- Use full disk encryption
- Only use the Ubuntu official repositories as Linux isn't invulnerable
and then you'll get rid of 99.9999% of hackers.
Fair warning: I didn't do all of the above (just some) but I use the most important security rule of all: Use common sense!