This type of hack called a “remote code execution flaw”. These allow hackers to run scripts on other players’ devices to gain full control of their system, which could then be used to nick data, wipe hard drives, or do whatever other harmful things hackers like doing with other peoples’ stuff. Secret Club show how this exploit could be triggered through a Steam invite in the Tweet below. It seems the hacker can send another player an invite, and when that player accepts, the hacker can open whatever they want on that player’s device. The scary part is that this was made possible due to a bug in the Source Engine, so any games made in that engine could’ve been affected (like CS:GO or Team Fortress 2). The group say that Valve have now sorted this exploit though, and the Secret Club member who discovered the hack, “Florian”, has been given permission to reveal the details about it. This hack-hunter says they’re currently working on a “detailed technical write-up”, so do keep an eye on their Twitter if you’re interested in the follow-up. Hopefully, this is the start of multiple remote code execution flaws being fixed by Valve, seeing as last week Secret Club also showed this type of exploit used in a few more ways. One involved hackers triggering the flaw inside malicious community servers in TF2. They’d be able set up a server, then send remote code executions to everyone inside it. There are also multiple ways it can be used in CS:GO.
