Game Hacking – Valve Anti-Cheat (VAC) • Hacker News Board

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

#61

Post by kevingadd » Wed, Jun 18, 2025, 9:45 PM UTC

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.

One anecdote: I "cheated" at EVE Online by writing an elaborate set of modding tools. Most of it was automation for really finicky tedious stuff like drone management, or automation for things like broadcasting your current target to other players in your party. I also hacked in workarounds for bugs in the official client. It enhanced my experience with the game a lot. On the other hand, lots of players were just botting.

I also maintained a browser addon for a while that had 100k+ weekly active users that added various features to a browser-based game. Eventually that game had such bad problems with botting and cheating that they had to introduce an anti-cheat system, and we basically got into a little arms race for a year or so where they'd add a new detection system and I'd circumvent it. Similar to the EVE Online modding it was things like workarounds for bugs in the game, improved UI, keyboard shortcuts, etc. Eventually they drew a line in the sand and said anyone using addons of any kind would get a permanent ban, so that was that.

I think the vast majority of cheaters are just in it to ruin other people's fun but sometimes people are violating ToS for a better or different experience with the game. It's unfortunate that the prevalence of malicious cheating means that anti-cheat technology also has to basically ban modding for fun.

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

#62

Post by tonyhart7 » Wed, Jun 18, 2025, 9:48 PM UTC

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…

how is this any different than the Google sells your data to Ads centre????

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

#63

Post by [deleted] » Wed, Jun 18, 2025, 9:54 PM UTC

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.

[deleted]

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

#64

Post by nyanpasu64 » Wed, Jun 18, 2025, 10:01 PM UTC

henrebotha wrote: post #11

eGQjxkKF6fif wrote: post #7

When VAC was originally introduced, CPUs only had 32bit architecture, not that 64bit hindered anything; but you could inject cheats in a near infinite amount of way, or have cheats read from memory directly, or have cheats do things especially through video drivers. Hell, glitching your nvidia drivers and setting things like Negative LOD Bias would allow you to see through textures in some cases (wall hacks) It's bee…

Yet another reason why fighting games are the superior competitive scene. The only "cheat" you could realistically see at an offline event is macros, and the chances of a macro increasing your win rate are slim to none. And there are so, so many good offline events. Online there are more potential ways to cheat, but nobody really cares. Just blacklist the player and move on.

Reminded of the Super Pichu story where someone modded his ISO of Melee to increase Pichu's stats during a Melee tournament.

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

#65

Post by zeta0134 » Wed, Jun 18, 2025, 10:15 PM UTC

Sohcahtoa82 wrote: post #57

zeta0134 wrote: post #24

Earlier quoted context omitted.

I'll chime in here as a game developer: my upcoming release will be an NES cartridge[0] and probably a Steam app. I'll be adding no DRM, because I generally trust that folks that weren't going to pay aren't going to be converted by its presence, and that honest folks want to support my work. Whether the storefronts I release on add their own is up to them, and frankly I don't care. Separately though, anti-cheat is an…

> Generally I favor "cheat detection should be serverside, don't trust the client" from a general security perspective, but... I can totally see a valid case in there, somewhere, for more rigorous clientside checks. Yeah... The simple fact is, it's simply not possible to have completely server-side cheat detection simply because you'll be relying purely on heuristics which could very well be wrong. It's just not goin…

And the counter is fairly straightforward: any client-side cheat detection has been broken. You can't trust the client. It doesn't work, your server just thinks it works because it's lying to you now.

Client-side cheat detection can work for tournaments, but it's way simpler there: the tournament provides the hardware, and the players aren't permitted to install anything. This doesn't irritate me quite as much from a security perspective of course, because I am not about to log into my banking site on the presumably insecure tournament device. It's also imperfect: a sufficiently motivated pro player might bypass whatever locks you installed on the thing, especially if they get to spend any time with that device unmonitored.

Even better than that, tournaments have a way better cheat detection method anyway: point a camera at the player's hands. It's suddenly really, really obvious if they're cheating!

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

#66

Post by bravetraveler » Wed, Jun 18, 2025, 10:17 PM UTC

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.

I, quite literally, got a career! Started as a technical curiosity, gave me in-roads to very weird corners of the internet. Got to know many professionals I wouldn't have, otherwise.

Ultimately served as the most effective networking I ever did.

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

#67

Post by invokestatic » Wed, Jun 18, 2025, 10:22 PM UTC

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…

Actually, VAC handles Cheat Engine and the like very well. You won’t get banned for simply having them open, only for having them attached to the game, which I think is reasonable.

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

#68

Post by jokoon » Wed, Jun 18, 2025, 10:25 PM UTC

I stopped playing because I felt I could not trust other players, I was getting too paranoid. There were not that many blatant cheaters, but with closet cheaters, it's now very difficult to know if your opponent is better than you or cheating in subtle ways. It's a grey zone.

I guess it's the combination of a frustration of losing matches and the constant suspicion. I was constantly trying to probe things and watching replays, it ruined the game because I was always focusing on cheating.

Ultimately, I think most CS players don't really care about subtle/closet cheaters, so as long as they don't feel it, it's fine, the game keeps its high player count, so it's a good facade and valve is happy with that.

CS is a game I can really enjoy, until I couldn't anymore.

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

#69

Post by ZeWaka » Wed, Jun 18, 2025, 10:27 PM UTC

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…

Interesting, a friend of mine did that in GMod, leading to the infamous 'cough' virus. (Yes, all the 'journalism' around this is wrong, and it's not the person commonly blamed for it).

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

#70

Post by doublerabbit » Wed, Jun 18, 2025, 10:28 PM UTC

Not quite CS, but I was part of a hacking scene that used to exploit C&C Red Alert 2, YR via Teds Relay and discovering the IRC lobby password being "supersecret".

Fun times were had as a script kiddie spawning the president and placing it in an IFV and just go demolishing the other players base with this fancy laser. But hey, I was 15 at the time.

Habbo Hotel too, being part of a "mafia" with a habbo multi hacker app; the flicker glitch that made your character blink causing lag. That and placing furni in rooms in the walls using ArtMoney filters. I discovered perl while messing with MSN bots; I miss those ages.

Others include NeoPets and Flash game hacking including RCEing the Money Tree claiming the loot before anyone else. Then I discovered IRC and Rx/PHAT botnets infecting via Windows 98 DCOM/NetSend exploits.

Tried it at school and next thing two of the colleges rejected my application, parents called and banished from using any computer in secondary school for the next two years. The college I went to was low-level polytechnic but the couple of the lecturers I had noticed my skill and homed me on a different path than being a BlackHat.

My moral compass kicked in and even now it's an itch I really want to scratch nowadays but PenTesting/CyberSecurity are too "prestigious" that the only chance is to fall in to.

So I've been an Sys/Unix Admin for past 18 years watching the world burn. I was using Linux (Debian/Slackware) when the kernel was at version 2 and Xorg was XFree86.

Luckily FreeBSD 8 gave me some fresh air after some IRC user rooted my box hosting my IRCd (on 56k) and did the honours of replacing Debian Linux with Debian kBSD. They left me a PM on IRC telling me to stay out of trouble and I've been using FBSD ever since. I'm 36. Never saw them again.

"Hey kid, stay out of trouble. btw your irc is down".

I will always remember that message waking up to a login MoTD with new root/password of some strange OS I had never used. I was angry that I lost my five botnet (T2 army) but I am grateful nowadays for it saving grace.

Not until many years later, I couldn't work out how they did until I came across of a backup of my early PHP3 script that allowed you to issue commands to the host. Apache was running as root and this was hosted in a public web directory (doy).