Cheat Engine Forum Index Cheat Engine
The Official Site of Cheat Engine
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 


Prevent a game Launcher from detecting another instance

 
Post new topic   Reply to topic    Cheat Engine Forum Index -> General Gamehacking
View previous topic :: View next topic  
Author Message
ulysse31
Master Cheater
Reputation: 2

Joined: 19 Mar 2015
Posts: 324
Location: Paris

PostPosted: Tue May 17, 2016 4:19 am    Post subject: Prevent a game Launcher from detecting another instance Reply with quote

Hi, I am using an online game which has a launcher on UE and one on NA, detecting each others on the OS (ie you cannot launch NA launcher if UE or NA launcher is already open and vice versa). Both launchers are developed by the same company.

And so I am curious as to how it can detect that a Launcher is already started, I have tried renaming the process and the window name, it doesn't impact detection. So I am wondering how else can this be done ?
My final goal being to hook the APIs which allow this detection to fake the result.
Back to top
View user's profile Send private message
Dark Byte
Site Admin
Reputation: 470

Joined: 09 May 2003
Posts: 25788
Location: The netherlands

PostPosted: Tue May 17, 2016 6:30 am    Post subject: Reply with quote

run the other game in a virtual machine.

or use process explorer and see if it creates named objects and see if you can do something about it. (e.g hooking the launcher exe on creation, and then do a api hook)

_________________
Do not ask me about online cheats. I don't know any and wont help finding them.

Like my help? Join me on Patreon so i can keep helping
Back to top
View user's profile Send private message MSN Messenger
ulysse31
Master Cheater
Reputation: 2

Joined: 19 Mar 2015
Posts: 324
Location: Paris

PostPosted: Tue May 17, 2016 8:14 am    Post subject: Reply with quote

Dark Byte wrote:
run the other game in a virtual machine.

Don't need that, I have RE'd this launcher a while ago with MIM attack (ie I have a 32 bit console that logs in and passes auth token + server list to process, am only doing this exercise for entertainment
Dark Byte wrote:

or use process explorer and see if it creates named objects and see if you can do something about it. (e.g hooking the launcher exe on creation, and then do a api hook)


Will do, for now i have unpacked the launcher and performed IDA analysis that has taught me after a createMutex and a Waitforsingleobject API, the message box with the string "only one instance of this program can be executed" gets executed depending on conditionnal jump.
Also trying to find out if it's scanning strings in window classes
Back to top
View user's profile Send private message
atom0s
Moderator
Reputation: 205

Joined: 25 Jan 2006
Posts: 8587
Location: 127.0.0.1

PostPosted: Tue May 17, 2016 1:03 pm    Post subject: Reply with quote

There are various ways it can detect another instance:
- Mutex instance.
- Semaphore instance.
- Named pipe.
- MMF
- Process scanning.
- FindWindow scanning for a window name/class.

The most common used method that I've seen with games is the mutex method.

_________________
- Retired.
Back to top
View user's profile Send private message Visit poster's website
ulysse31
Master Cheater
Reputation: 2

Joined: 19 Mar 2015
Posts: 324
Location: Paris

PostPosted: Tue May 17, 2016 2:33 pm    Post subject: Reply with quote

Some hints tend for a mutex method, at least that's what an IDA function shows. However I am cautious about my unpack because it doesn't actually launch correctly (its an upx SFX ZIP packed exe with signature and certificate which makes it too hard to unpack for me).

But there is also something fishy on the TCP connections ie i noticed the real launcher window has plenty connections among which 2 TCP that are listening to the own local computer while the error launcher only has 1 connection which is also listening to the computer and has just a few bytes of traffic.
=> i am guessing something similar to what IDA does to spot other network sessions with same key but here only on the same computer.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Cheat Engine Forum Index -> General Gamehacking All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group

CE Wiki   IRC (#CEF)   Twitter
Third party websites