Reverse engineer Ford IDS (find SecurityAccess algo)
Posted: 11 Feb 2024, 08:40
Have you every tried to decrypt "MCPFunctionManager.dll" ? I know that inside we would find the security algorithm for UDS 0x27 (SecurityAccess). I could already get the "keybag" from "AlgData.dll", but it's worthless without the algo.
Currently i don't really know where to start. Tried to load the DLL into IDA but it won't show up much in the "Exports" section, so i assume the DLL is somewhat packed/encrypted. As always, a base understanding, knowledge and analysing tools are required to start such a journey. I found a neat tool called "DIE - Detect It Easy" here
https://github.com/horsicq/Detect-It-Easy (https://github.com/horsicq/DIE-engine/r ... 09_x64.zip) which give some insights of a file loaded.
A "DLL" is somewhat similar to an "EXE", it could contain data, resources and code. DIE tells this about the file: Looks pretty handsome and not crypted in first, but why does IDA complain about the file and could not get the functions inside?
Compared with loading "forscan.exe" for example, you see DIE finds the protection: So this is something "special" inside MCP*.dll. DIE has a entropy-graph tool. You can detect enrcyptions with it. Don't know how that works, but the higher the value the more likely the content is crypted somehow. The graph is clear about what is in the ".text" part of the PE:
Currently i don't really know where to start. Tried to load the DLL into IDA but it won't show up much in the "Exports" section, so i assume the DLL is somewhat packed/encrypted. As always, a base understanding, knowledge and analysing tools are required to start such a journey. I found a neat tool called "DIE - Detect It Easy" here
https://github.com/horsicq/Detect-It-Easy (https://github.com/horsicq/DIE-engine/r ... 09_x64.zip) which give some insights of a file loaded.
A "DLL" is somewhat similar to an "EXE", it could contain data, resources and code. DIE tells this about the file: Looks pretty handsome and not crypted in first, but why does IDA complain about the file and could not get the functions inside?
Compared with loading "forscan.exe" for example, you see DIE finds the protection: So this is something "special" inside MCP*.dll. DIE has a entropy-graph tool. You can detect enrcyptions with it. Don't know how that works, but the higher the value the more likely the content is crypted somehow. The graph is clear about what is in the ".text" part of the PE: