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Game Hacking – Valve Anti-Cheat (VAC)

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Re: Game Hacking – Valve Anti-Cheat (VAC)

#41

Post by mschuster91 »

garrettjoecox wrote: post #9

Years ago for educational purposes I decided to venture down understanding how easy/difficult it was to create a hack for Counterstrike. After just a few hours of watching YouTube tutorials and translating what I could grasp from C/C# into JavaScript (the only language I knew at the time), I had a working Node.js executable that edited memory offsets (using data from hazedumper[1]), letting me see enemies through wal…

> I only toyed with it for a few weeks as I then grew disinterested but that definitely left a sour taste in my mouth for the "effectiveness" of VAC if a script kiddie like me at the time could throw together something custom in just a few hours, I'm sure it'd be much easier now with ChatGPT...

The thing is, VAC doesn't immediately ban you. Or anyone else. It's looking for suspicious patterns across hundreds if not thousands of players and collecting evidence over weeks if not months to make sure they got relatively low false-positive rates and don't end up banning people for a Windows update gone wrong... and additionally, it raises the iteration time for cheat developers as well, and that's the true point. Show cheaters immediately that they're spotted and the only thing you enter is an immediate arms race.

Your way of writing a cheat was probably detected but since no one else used it, VAC didn't trigger.

Re: Game Hacking – Valve Anti-Cheat (VAC)

#43

Post by keyringlight »

snickerdoodle12 wrote: post #10

Remote Code Execution like loading DLLs from a server and executing them sounds like malware.

I'm surprised there haven't been more events of mods and tools being used as trojans. For all the concern about anti-cheat/DRM, PC gamers seem very selective over what sources of code they're running on their computers they scrutinize. There's an awful lot of users with "just enough" levels of knowledge where I think a tempting enough release with the right timing for a hot game could get a lot of installs.

Re: Game Hacking – Valve Anti-Cheat (VAC)

#44

Post by Ekaros »

mschuster91 wrote: post #41
garrettjoecox wrote: post #9

Years ago for educational purposes I decided to venture down understanding how easy/difficult it was to create a hack for Counterstrike. After just a few hours of watching YouTube tutorials and translating what I could grasp from C/C# into JavaScript (the only language I knew at the time), I had a working Node.js executable that edited memory offsets (using data from hazedumper[1]), letting me see enemies through wal…

> I only toyed with it for a few weeks as I then grew disinterested but that definitely left a sour taste in my mouth for the "effectiveness" of VAC if a script kiddie like me at the time could throw together something custom in just a few hours, I'm sure it'd be much easier now with ChatGPT... The thing is, VAC doesn't immediately ban you. Or anyone else. It's looking for suspicious patterns across hundreds if not t…

I haven't followed recently, but what I have understood is that clear known old public hacks can result immediate ban. For newest hacks they will gather cohort and then do them in wave. Thus making it harder to evade detection or notice what exactly was detected this time.

Re: Game Hacking – Valve Anti-Cheat (VAC)

#45

Post by bob1029 »

qualeed wrote: post #12
bob1029 wrote: post #5

I am not a fan of the signature-based techniques used by VAC, et. al. I've lost a few steam accounts to accurate but unintended (i.e., not actually cheating) detection of debugging tools attached to totally unrelated processes on the same machine. Having anything open like cheat engine or Tsearch while you join a lobby is a guaranteed ban no matter what. Ethical hacking and malicious hacking are indistinguishable fro…

> If someone at Valve had taken 10 seconds to review my stats It seems super reasonable when it's a one-off thing for your own account. When you think about making it into policy and scaling it up to 1000s of interactions, it quickly becomes unreasonable. > Statistical techniques can dramatically reduce false positives For a period of time, anyways. Until the statistics get gamed by the cheaters (e.g. adjust accuracy…

> adjust accuracy of your auto-shoot from 100% to 85% or whatever

Sure - looking at K/D, accuracy, etc., is an important factor in a statistical model.

Statistics can also include: Map name, player transform on the map, keyboard and mouse events, GPU utilization, audio playback events, etc. These are all very high information time domain signals that can be correlated with the same from any other player.

After a certain point, I don't think it matters if it is publicly known what your signals are. The amount of information becomes overwhelming in aggregate. You can impose the curse of dimensionality on the cheater.

Re: Game Hacking – Valve Anti-Cheat (VAC)

#46

Post by hnlmorg »

debugnik wrote: post #37
hnlmorg wrote: post #35

Earlier quoted context omitted.

> Around then was when I decided to start gaming from a VM lol How? Maybe I’m getting my dates mixed up but CS was released in the late 90 / early 90s and consumer virtualisation wasn’t nearly good enough to game in for another 10 years. Consumer CPUs didn’t have virtualisation extensions and GPU paravirtualisation wasn’t available either in the early 2000s. VMWare wasn’t even any good for just running Windows 2000 (…

They said Counter Strike: Source, that's 2004-2013. I'm still curious though, if it worked at all performance must have been awful.

Ahhhh, that makes a lot more sense. Thanks

Re: Game Hacking – Valve Anti-Cheat (VAC)

#47

Post by qualeed »

stoorafa wrote: post #33
qualeed wrote: post #12

Earlier quoted context omitted.

> If someone at Valve had taken 10 seconds to review my stats It seems super reasonable when it's a one-off thing for your own account. When you think about making it into policy and scaling it up to 1000s of interactions, it quickly becomes unreasonable. > Statistical techniques can dramatically reduce false positives For a period of time, anyways. Until the statistics get gamed by the cheaters (e.g. adjust accuracy…

Computation isn’t likely prohibitive when using the bedrock of predictive models, linear regression, especially w some optimization. Could also vary observation time so you only need a prediction once every ten minutes or whatever The real issue is the cost of false positive detection of cheating is negligible since the vast majority of positives are probably true positives—it’s the cost of doing anti-cheat business…

>Computation isn’t likely prohibitive when [...]

I think this might be in reply to my first comment about scaling? If so, I just want to clarify that I was thinking more along the lines of scaling the customer service/ban appeal side rather than infrastructure.

If, for example, every ban had a component of someone at Valve taking 10 seconds to review in-game stats at the time of the ban, and then making a determination of whether or not those stats seem reasonably non-cheater-ish (pretty hard policy question in itself), the process would slow to a crawl.

Re: Game Hacking – Valve Anti-Cheat (VAC)

#48

Post by Nextgrid »

SteveNuts wrote: post #30
garrettjoecox wrote: post #9

Years ago for educational purposes I decided to venture down understanding how easy/difficult it was to create a hack for Counterstrike. After just a few hours of watching YouTube tutorials and translating what I could grasp from C/C# into JavaScript (the only language I knew at the time), I had a working Node.js executable that edited memory offsets (using data from hazedumper[1]), letting me see enemies through wal…

I'll never understand what people actually get out of cheating in games. I'll admit I've tried it a few times just for giggles (way back in the Age of Empires II/MSN Gaming Zone days), but the novelty quickly wears off and then it's just not even fun anymore. There must be some very interesting psychology behind this.

In games where available weapons/gear depends on some global "level", this could be a way to get your desired weapons without having to grind for weeks/months. I guess a silver lining of "pay to win" games is that you can now pay to avoid that.

I remember trying to hack the levelling-up mechanism on Crysis 2 - it worked by sending your post-game stats (client-side) to a master server, so editing those stats in memory before that happens would work (there seems to be no tracking of stats on the game server side - even though they could've had the game server relay that to the master server).

Memory is fuzzy but I think I managed to level up to a stage where I got the weapons I wanted. For my defense this kind of "cheating" only "cooked the books" on the leaderboards and did not give me any actual advantage in-game.

Re: Game Hacking – Valve Anti-Cheat (VAC)

#49

Post by WilcoKruijer »

malwrar wrote: post #26
rimunroe wrote: post #21

Back in 2000-2005 I was very active in a community centered around 20 or so modded Counter-Strike servers which I volunteered as an admin on. We were generally good about having at least one admin on each server at any given time to deal with cheaters. Occasionally someone wouldn’t be around though. There was a period of time lasting about a month or two where a player with a name like BELT SANDER or ANGLE GRINDER or…

I used to write cheats for CSS & other Source games. Not sure if the original CS would have the same vuln, but iirc you used to be able to use an INetChannel::ReceiveFile function with path traversal to grab the server config. There were a few cool hacks around the file path filtering logic they added in my era that (combined with ::SendFile) enabled a fun period of arbitrary RCE on Source servers. I knew one person…

This exploit has its origin in the Quake engine. I remember exploiting the same thing in CoD4 (2007) and I believe even the release version of Black Ops I was vulnerable. It was known as the ‘q3dirtrav’ vulnerability.

Re: Game Hacking – Valve Anti-Cheat (VAC)

#50

Post by snickerdoodle12 »

rvnx wrote: post #17
snickerdoodle12 wrote: post #10

Remote Code Execution like loading DLLs from a server and executing them sounds like malware.

It's "just" an automatic update, like Chrome, etc. It's one entry-point among others for RCE. If tomorrow NSA wants to gather any files on your computer, all they need to do is to ask Google to push an update for you through Google Omaha. https://epic.org/wp-content/uploads/privacy/nsa/foia/NSA-Goo... Google and NSA have a "partnership". Valve could also have such partnership in theory, through VAC, though unlikely i…

I get chromium & firefox from my distro's repos
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