I'm not havin' it.
I'm fed up with the ammount of GMod backdoors/server takeovers I keep finding.
This is a database of all the ones I've found in GMod workshop addons etc.
This information should help people trying to protect their servers from this crap.
You should read and understand all code you run on your servers.
DO NOT TRUST THE WORKSHOP. Scripts can update silently and add backdoors.
See the folders for information about each one.
EDIT 2016:
It seems a few clientside GMod hacks now have backdoors too..
./BD001_gpwn_new - gpwn backdoor, quite complex.
./BD002_Underdone - Underdone backdoor/DRM annoyance script.
./BD003_rp_nexusgrad_v1_winter - rp_nexusgrad_v1_winter map backdoor.
./BD004_TPC_Updated - Updated version of the Third Person Controller backdoor / Server takeover script.
./BD004_ThirdPersonController - Third Person Controller backdoor / Server takeover.
./BD005_Vorox_Goodman - Vorox Goodman backdoor / Server takeover
./BD006_Pon_Bootstrap - Pon bootstrap backdoor / Server takeover
./BD007_Next_Level_Bigpayload - Next_level Bigpayload backdoor / Server takeover
./BD008_Demonic_King - Demonic King Backdoors / Server takeovers
./BD009_Hammerfist_Hammerfall - Hammerfist Hammerfall Backdoor
./BD010_French_Weapon_Scripts - French weapon scripts annoyance
./BD011_IdiotBackdoor - The dumbest one yet
./BD012_DoorHandler - Another crappy server takeover
./BD013_CPT_Base - Harmless but annoying chat spammer
./BD014_Obfuscated_hud - Obfuscated hud? not sure about this one
./BD015_CW2_non_original - Basic concommand & steamIDs
./BD016_GCap - Basic concommand
./BD017_Crash - Admin giver
./BD018_AfterShock_Gaming - Annoyance & server takeover
./BD019_HTX_Hostile_Takeover_Exploit - Server takeover with client menu
./BD020_Dumb - Another dumb HTTP RunString one
./BD021_ShittyScripts - Clientside backdoor'd cheat!
./BD022_TraitorGlow_Again - Server takeover / Unbanner
./BD023_gmeme_clientside_Backdoor - Clientside cheat backdoor