Degrees of compromise

• Externally visible
  • run more-or-less arbitrary commands as root
  • run more-or-less arbitrary commands as ordinary user
  • distribute files via your web server or ftp server
  • use your machine to proxy some type of IP traffic
  • relay spam mail via your machine
• Not externally visible
  • delete arbitrary files as root
  • hang, halt, or reboot your machine
  • kill arbitrary processes as root
  • terminate arbitrary network connections as root
  • otherwise make machine less functional to users