If there is a site that should be listed here or if a link goes dead, .

Tauscan bolts the backdoor to your computer

• AckCmd : remote command prompt using only TCP ACK segments to pass firewalls W2K , free
  
• Backdoor Trojans
  
• Backdoors Tutorial
  
• BackOrifice : remote administration system free
  
• BOPing : scanner for Back Orifice program NT, free, www.foundstone.com
  
• Cleaner : Trojan detection and removal
  
• Deepthroat open source
  
• Detecting Backdoors
  
• Firewalls: Placing Backdoors Through Firewalls
  
• Hacker-spiders
  
• Netbus
  
• Netware Logging and Backdoors
  
• Network Security: Backdoors
  
• Russian backdoor site
  
• Tini: Very small (3kb) telnet server backdoor for Windows
  NT, Win9x, W2K, free