A Simple Trick Allowed 'Counter-Strike' Players to See Through Walls

Cheaters could take advantage of a trivially easy to use hack in Counter-Strike: Global Offensive that made opponents visible even through walls, which made it much easier to kill them and win games. 

At the end of July, a Twitter user claimed that a friend of his had found a “legal wallhack” on Counter-Strike: Global Offensive that made opponents visible through walls. Wallhacks are cheats that allow hackers to see opponents through obstacles in online games. Motherboard was able to reproduce the cheat and verify that it’s indeed possible to turn opponents visible at all times. After reaching out to Valve to ask for comment, the cheat was fixed this week. 

Usually, in order to employ cheats like this one, gamers pay for cheats from developers or resellers online, who usually offer monthly subscriptions with the promise of giving continuous support in case the cheat gets detected. These cheats usually rely on flaws or bugs within video games’ code, or sorting through game code on the user's end. 

“First time I discovered this exploit [was] in 2019,” the person who found the cheat, who goes by the name DepoSit, told Motherboard. DepoSit does not speak English and talked via a friend who translated his Russian. “Then, from time to time I've checked if this bug is still working…One year later, there wasn't any patch pushed to fix this problem.”

An employee of a gaming company who works on anti-cheat efforts and asked to remain anonymous as they were not allowed to talk to the press, said that this cheat consists of replacing “the shader that draws enemies with one that always draws on top of everything else (including walls).”

“The trick is that the game file integrity check seems to be done on joining a match but when shader settings are changed the game will happily reload the (now tampered with) content file without doing another integrity check,” the employee said. “Sometimes cheats can be really simple.”

Gabe Follower, the Twitter user who posted the video of the cheat, explained step by step how to use this cheat. Motherboard was able to reproduce it earlier this week. The procedure involved replacing a file within the games’ directory and then changing a setting within the game, without any need to know how to reverse engineer code or write an exploit. Gabe Follower also said he reported the issue to Valve this week, but the company has yet to get back to him. On Friday, Gabe Follower said the cheat was fixed, and we were not able to take advantage of it anymore.  

A YouTube video from 2011 shows that the same hack also worked for a different Valve game, Team Fortress 2. 

Valve did not respond to a request for comment.  

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