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Bypass VAC ban

Posted: Mon Oct 24, 2016 5:40 pm
by Koppara
Is it possible to bypass VAC ban? I'm just curious as I've seen people talk about this, but never seen a program / proof that this is possible to do.

Re: Bypass VAC ban

Posted: Wed Nov 02, 2016 6:33 pm
by Sethioz
everything is possible, you just gotta do research and see how it works.
I haven't done any research on VAC, but most likely it simply bans your game serial, so when you try to join a server with that serial, you get kicked.

from what i know, you can use packed editors to make server think you are not banned. For example in some older games, when server sent you a message "you're banned", but you modified your game client to ignore that message, then server still accepted the packets after that, still allowing you to join.
It's a lot of work and i don't think anyone would do this just for the fun of it and if they do, they wouldn't release it in public cuz it would get patched very fast.

VAC ban is same as any other ban, so i'm quite sure it bans your serial and that's it.
There are many ways to try and bypass any type of ban, but you need to know how to debug the game and its protocol and find out how the system works and then try to manipulate it. For example in some games you can steal somebody's "session id", like stealing cookies on websites and then use that, so you join as someone else, while still playing from your own account.

If game has specific check towards the serial, then i don't think you can unban yourself. For example like Wireless WPA2 authentication works with 4-way handshake, where you router sends you decrypted data and your client encrypts it with the key you provide, then you send the encrypted data back and router compares that data to the data it encrypted itself with the right key, so if they match, then router communicates with the client, however router always sends the encrypted files after that, so even if you make router think that you had right key (which doesn't happen), then you still get encrypted data which you can't decrypt. so check is done on the router side.

Same method is used in some games and websites, where check is made on server side and there's nothing you can do about it.

Re: Bypass VAC ban

Posted: Thu Nov 03, 2016 4:10 pm
by Koppara
Ok, interesting. Yep, the ban apply straight to your Steam account. The game automatically blocks your communications with the online multiplayer game servers.

You cannot just "steal" someones session ID, am I right? You have to a website or something else to get their info, as use it yourself?

A good way to use 'hacks' which I found out a bit late, is DLL Hijacking where you can use cheats which are loaded by legit applications, so it's basically exploiting applications that try to load non-existent DLL's

Re: Bypass VAC ban

Posted: Fri Nov 04, 2016 5:17 pm
by Sethioz
Well in most games, server always sees the necessary info, so if you host your own server, you can collect info. As far as i know, server has all the info necessary to join and play. Some games are so badly made, that they display the serial directly, however most games should have it encrypted and it shows as "session id", but it doesn't really matter, cuz if you can replicate that when joining, then server would think that someone else is joining.

On steam i'm sure it's difficult, but it's possible.
VAC scans the checksums of each important DLL / EXE file, so injecting something into dll or exe will still get you banned. VAC also scans for the .text area of .exe (it's where static instructions are kept), so modifying those will also get you banned.

Only VAC secure method i'm aware of, is to use pointer scans and then use 3rd party tool to find them and write your own value. I used Luigi's QuickBMS and one of his scripts he wrote for me to find and write values in memory. I found them with cheat engine, but CE is detected by VAC, so I used QuickBMS script to find the pointers and then write my values, such as like health to 99999 ..etc. It was a cmd script, so i minimized the game, ran the script and it did the thing within like 100ms or less and then closed, there's no way VAC would detect this.
but unbanning .. it wouldn't help.

Re: Bypass VAC ban

Posted: Mon Nov 07, 2016 3:42 pm
by Koppara
Yeah, I see. Doesn't seem that it's the easiest thing to do, but I guess that there is always a way to do things with computers and software.

Thanks for your answers!