Over 40,000 Dota 2 accounts have been permanently banned in the last few weeks after they were caught red-handed using third-party software to cheat the game. In a blog post published on Tuesday, Valve revealed that it had recently patched a known issue used by third-party software to cheat in Dota while simultaneously setting a honeypot trap to catch players using the exploit.

According to Valve, the cheating software gave its users an unfair advantage by accessing information used internally by the Dota client that shouldn’t be visible during gameplay. After investigating how it worked, the developer then decided to identify and remove the “bad actors” from the active Dota playerbase. 

“We released a patch as soon as we understood the method these cheats were using,” Valve said. “This patch created a honeypot: a section of data inside the game client that would never be read during normal gameplay, but that could be read by these exploits.” Valve claims that all 40,000 of the now-banned accounts had accessed this hidden section of data, and that it had “extremely high confidence that every ban was well-deserved.”

Valve highlighted that the number of accounts banned was especially significant due to how prevalent this particular family of cheating clients is, and that the action taken is just one step in an ongoing campaign to tackle those abusing the popular MOBA game. “While the battle against cheaters and cheat developers often takes place in the shadows, we wanted to make this example visible, and use it to make our position clear: If you are running any application that reads data from the Dota client as you’re playing games, your account can be permanently banned from playing Dota,” warned Valve.

Valve is far from the only gaming giant trying to combat cheaters within its playerbase. Ubisoft announced this week that it’s developed a system to “mess” with players who cheat using XIM devices, increasing latency to interfere with the player’s aim. Destiny 2 developer Bungie also won over $4 million in a lawsuit earlier this week after courts found that cheat maker AimJunkies had violated the developer’s copyright. Meanwhile, Riot Games issued a warning to League of Legends and Teamfight Tactics players earlier this year that new cheats could be developed after source code for both games and the legacy anti-cheating software they use was stolen in a data breach.