Online Game Security - Quake III and its Hacks - (related paper: A Systematic Classification of Cheating in Online Games, Jeff Yanand and Brian Randell. Submitted 2004) A Systematic Classification of Cheating in Online GamesA Systematic Classification of Cheating in Online Games Speaker: S. F. Yeung

Flow of this Presentation What is Game Hacks? What is Game Hacks? How do Hacks Work? How do Hacks Work? What can Hacks Do? What can Hacks Do? How to Fight Against Them? How to Fight Against Them? How Hackers Fight back ? How Hackers Fight back ? So, What ’ s Now? So, What ’ s Now? Possible Solutions Possible Solutions

What is Game Hacks (or cheats)? A program that alters a game ’ s performance A program that alters a game ’ s performance Enhancing the abilities of the hacker (or cheater) Enhancing the abilities of the hacker (or cheater) Giving an unfair edge over the other players Giving an unfair edge over the other players

What Hacks can/cannot Do ? Hacks can Hacks can –Reveal hidden information on the client side –Assist your mouse/keyboard control –Enhance your visibility or remove unwanted visual effect Hack cannot Hack cannot –Reveal information not exist in client side –Alter the rules and logics of the game –Alter the performance of other players

How do Hacks Work? –Hard Coded Modify the game code Modify the game code –External Retrieve information from the game indirectly and alter the control of the game indirectly Retrieve information from the game indirectly and alter the control of the game indirectly –Driver Hack Modify the video driver to gain special visual effect Modify the video driver to gain special visual effect –Client Hook Inject code into the game ’ s memory in runtime Inject code into the game ’ s memory in runtime

How do Hacks Work? Hard Coded Hard Coded –Modify the game code directly and permanently –Easily to be blocked Game ServerGame Program DATA Hack

How do Hacks Work? External External –Reside outside the game program –Limited functionality Game ServerGame Program DATA Color Model Windows Mouse Control Hack Windows Graphic Display Interface

How do Hacks Work? Driver Hack Driver Hack –Modify the OpenGL driver so that objects (including walls) become semi-transparent –Difficult and dangerous to install Game ServerGame Program DATA Hacked Video Driver Display

How do Hacks Work? Client Hook Client Hook The most advanced and popular today The most advanced and popular today Inject code into the game ’ s memory in runtime Inject code into the game ’ s memory in runtime Alter and control the game directly in runtime Alter and control the game directly in runtime Game Server Client Hook DATA Game Running

What can Hacks Do ? Wall Hack Wall Hack –See other players through walls Aimbot (aiming robot) Aimbot (aiming robot) –Lock your crosshair on other players automatically Firebot (fire robot) Firebot (fire robot) –Fire your weapon automatically once your crosshair hover over another player ESP (extrasensory perception) ESP (extrasensory perception) –Reveal and display hidden information

What can Hacks Do ? Wall Hack Wall Hack –Driver Hack Make everything semi-transparent, you can see others through walls, but everything become semi- transparent may not be good somehow Make everything semi-transparent, you can see others through walls, but everything become semi- transparent may not be good somehow –Client Hook Only show certain objects through walls, very effective Only show certain objects through walls, very effective

Full transparency Partial transparency

What can Hacks Do ? Aimbot and Firebot Aimbot and Firebot –External Colored object model Colored object model Scan the screen to locate target Scan the screen to locate target Interfere your control via Windows message Interfere your control via Windows message Not very intelligent and inaccurate Not very intelligent and inaccurate –Client hook Access the game engine in memory, obtain target position and take over your control directly Access the game engine in memory, obtain target position and take over your control directly Perfect accuracy if low network latency Perfect accuracy if low network latency

Colored object model

What can Hacks Do ? ESP ESP –Client Hook Radar ESP and Map ESP Radar ESP and Map ESP –Shows the location of enemies Text ESP Text ESP –Shows other players ’ name, weapon, armor and other variables

ESP showing Enemies ’ name, weapon and their locations

How to Fight Against Hacks? Pure Server Environment Pure Server Environment –Server will check against all game files, players joining the server must have the same config file, object models, sound files, etc. –Effective against hard-coded hacks and external hacks

How to Fight Against Hacks? 3rd Party Anti-cheating Software 3rd Party Anti-cheating Software –For example: PunkBustered (Quake III, RTCW) PunkBustered (Quake III, RTCW) UT Pure (Unreal Tournament) UT Pure (Unreal Tournament) VAC (Counter Strike) VAC (Counter Strike) –Players must install the anti-cheating software in order to join a anti-cheating enabled server –Acts like a virus scanner –Auto updates with the new hack patterns –Capture and send screenshots regularly –Banns your serial number if any hack found

How Hackers Fight back? Anti-cheating Software Proof Hacks Anti-cheating Software Proof Hacks –Cracks the anti-cheating software binary –Alters the behavior of the anti-cheating software –Automatically disable the hacks each time the anti-cheating software takes a screen shot

So, What ’ s Now? An update competition An update competition –Most hacks will be banned several days after public release –Major hacks will have new version few weeks after the previous one get banned

Possible Solutions Use secure network protocol Use secure network protocol –Add checksum between every packets, makes insertion or modification of packets difficult Encrypt all important variables Encrypt all important variables –Encrypt variables so that cheats cannot reveal information from the memory Push all computation to the server side Push all computation to the server side –The client side only responsible for user input and display rendering thus the cheats have no way to alter the state or outcome of the game

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