NProtect GameGuard

nProtect GameGuard (sometimes called GG) is an anti-cheating root toolkit developed by INCA Internet. It is widely installed in many online games to block possibly malicious applications and prevent common methods of cheating. nProtect GameGuard provides B2B2C (Business to Business to Consumer) security services for online game companies and portal sites. The software is considered to be one of three software programs which "dominate the online game security market".

GameGuard hides the game application process, monitors the entire memory range, terminates applications defined by the game vendor and INCA Internet to be cheats (QIP for example), blocks certain calls to Direct X functions and Windows APIs, keylogs keyboard input, and auto-updates itself to change as new possible threats surface.

Since GameGuard essentially works like a rootkit, players may experience unintended and potentially unwanted side effects. Since the game's process cannot be stopped from the task manager, if the protected game has an infinite loop or hangs in any way, it is effectively impossible to close without logging out or restarting the computer. This is even more frustrating since GameGuard checks if it is already running on the game's launch and does not permit the player to start a new instance in such cases. If set, GameGuard blocks any installation or activation of hardware and peripherals (e.g., a mouse) while the program is running. Since GameGuard monitors any changes in the computer's memory, it will cause performance issues when the protected game loads multiple or large resources all at once.

Additionally, some versions of GameGuard have an unpatched privilege escalation bug, allowing any program to issue commands as if they were running under an Administrator account.

GameGuard possesses a database on game hacks based on security references from more than 260 game clients. Some editions of GameGuard are now bundled with INCA Internet's Tachyon anti-virus/anti-spyware library, and others with nProtect Key Crypt, an anti-key-logger software that protects the keyboard input information.