• Design and Implementation of the Second Extended Filesystem:
  http://e2fsprogs.sourceforge.net/ext2intro.html
• Ways to hide files in ext2/3 filesystem (Chinese):
  http://www.linuxforum.net/forum/gshowflat.php?Cat=&Board=security&Number=54
  5342&page=0&view=collapsed&sb=5&o=all&vc=1
• Static Kernel Patching: http://www.phrack.org/show.php?p=60&a=8
• Infecting Loadable Kernel Modules: http://www.phrack.org/show.php?p=61&a=10
• Ways to find 2.6 kernel rootkits (Chinese):
  http://www.linuxforum.net/forum/gshowflat.php?Cat=&Board=security&Number=54
  0646&page=0&view=collapsed&sb=5&o=all&vc=1