Stops people downloading or uploading unauthorized files to your gameserver
Anything else.
Click here.
Drop the folders in the archive in the addons/sourcemod folder.
Orange Box Valve (Source 2009).
Some people won't use the full ServerSecure VSP due to the cosmetic ping time increase, this is also missing from the Linux version of ServerSecure and D-FENS has been proven to be bypassed.
The method is directly from ServerSecure and was writen by AzuiSleet. All I have done is split out the code and converted it to use a different Detours lib that is cross-platform.
Here.