- by x32x01 ||
Windows App Pentesting - Step-by-Step Ethical Guide 
Penetration testing for Windows apps is a crucial skill for security researchers, blue teamers, and ethical hackers. But remember - only test systems you own or have written permission to test. Unauthorized testing is illegal and unethical.
1. Scoping & Rules of Engagement
Always start with a clear written scope that defines what you can test, when, and how. Include rollback and emergency contact details.
Example:
“Test only
2. Reconnaissance (Information Gathering)
Identify the app type - is it .NET, native, UWP, or Electron? Collect everything: binaries, manifests, installers, and debug symbols. Don’t forget registry keys, scheduled tasks, and services that interact with the app.
3. Threat Modeling & Attack Surface
Map out all entry points - UI, sockets, COM, named pipes, and update services. Then identify sensitive assets such as credentials, encryption keys, and personal data.
4. Static Analysis
Use dnSpy or ILSpy for .NET apps, and Ghidra or IDA for native binaries. Review PE headers, resources, and manifests for secrets, packers, or suspicious code.
5. Dynamic Analysis (Runtime Recon)
Run the app in a VM snapshot for isolation.
Monitor everything with ProcMon, Process Explorer, Wireshark, and Fiddler to find leaked data or insecure connections.
6. Instrumentation & Debugging
Use Frida, x64dbg, or WinDbg to hook functions and inspect runtime logic.
For .NET, set breakpoints inside managed code to follow the authentication flow.
7. Authentication & Session Testing
Check how the app stores credentials or tokens - in files, the registry, or memory. Verify ACLs on named pipes or local APIs to prevent unauthorized access.
8. Authorization & Privilege Escalation
Attempt to trigger privileged actions from an unprivileged context.
Common issues include DLL hijacking, weak folder permissions, and misconfigured services.
9. Input Validation & Memory Safety
Fuzz every input vector: files, IPC messages, or sockets. Watch for crashes, buffer overflows, and format-string issues - key signs of unsafe parsing.
10. Unsafe Deserialization
Beware of unsafe BinaryFormatter or custom deserializers. They can instantiate arbitrary objects and lead to code execution.
11. Cryptography & Secure Storage
Check if encryption keys are hardcoded or stored insecurely. Avoid MD5, SHA-1, or ECB mode - use modern algorithms and DPAPI correctly.
12. Update Mechanism & Supply Chain
Verify all updates use TLS and code signing. Updates over HTTP or unsigned installers are critical security failures.
13. Driver & Kernel Components
If the app includes kernel drivers, carefully inspect IOCTL handling. Always use a sandbox to avoid system crashes or privilege escalations.
14. Persistence & Post-Exploitation (Ethical)
Only document persistence risks - never deploy real payloads. Suggest defensive hardening and provide mitigation examples.
15. Reporting & Recommendations
Rate findings as Critical / High / Medium / Low.
Include:
16. Hardening Checklist
17. Essential Tools
Sysinternals Suite • Wireshark • Fiddler • Burp Suite • Ghidra • dnSpy • IDA • x64dbg • Frida • AFL/boofuzz
18. Example Case
App:
19. Reporting Template
In summary:
This cheat sheet helps ethical hackers perform full Windows app pentests - from static and dynamic analysis to fuzzing, crypto testing, and secure reporting. Use it to strengthen defenses, not to exploit vulnerabilities.
Penetration testing for Windows apps is a crucial skill for security researchers, blue teamers, and ethical hackers. But remember - only test systems you own or have written permission to test. Unauthorized testing is illegal and unethical.
1. Scoping & Rules of Engagement 
Always start with a clear written scope that defines what you can test, when, and how. Include rollback and emergency contact details.Example:
“Test only
A.exe on 10.0.0.5 between 2025-09-25 and 2025-09-27.”2. Reconnaissance (Information Gathering) 
Identify the app type - is it .NET, native, UWP, or Electron? Collect everything: binaries, manifests, installers, and debug symbols. Don’t forget registry keys, scheduled tasks, and services that interact with the app.3. Threat Modeling & Attack Surface 
Map out all entry points - UI, sockets, COM, named pipes, and update services. Then identify sensitive assets such as credentials, encryption keys, and personal data.4. Static Analysis 
Use dnSpy or ILSpy for .NET apps, and Ghidra or IDA for native binaries. Review PE headers, resources, and manifests for secrets, packers, or suspicious code.5. Dynamic Analysis (Runtime Recon) 
Run the app in a VM snapshot for isolation.Monitor everything with ProcMon, Process Explorer, Wireshark, and Fiddler to find leaked data or insecure connections.
6. Instrumentation & Debugging 
Use Frida, x64dbg, or WinDbg to hook functions and inspect runtime logic.For .NET, set breakpoints inside managed code to follow the authentication flow.
7. Authentication & Session Testing
Check how the app stores credentials or tokens - in files, the registry, or memory. Verify ACLs on named pipes or local APIs to prevent unauthorized access.8. Authorization & Privilege Escalation
Attempt to trigger privileged actions from an unprivileged context.Common issues include DLL hijacking, weak folder permissions, and misconfigured services.
9. Input Validation & Memory Safety 
Fuzz every input vector: files, IPC messages, or sockets. Watch for crashes, buffer overflows, and format-string issues - key signs of unsafe parsing.10. Unsafe Deserialization 
Beware of unsafe BinaryFormatter or custom deserializers. They can instantiate arbitrary objects and lead to code execution.11. Cryptography & Secure Storage 
Check if encryption keys are hardcoded or stored insecurely. Avoid MD5, SHA-1, or ECB mode - use modern algorithms and DPAPI correctly.12. Update Mechanism & Supply Chain 
Verify all updates use TLS and code signing. Updates over HTTP or unsigned installers are critical security failures.13. Driver & Kernel Components 
If the app includes kernel drivers, carefully inspect IOCTL handling. Always use a sandbox to avoid system crashes or privilege escalations.14. Persistence & Post-Exploitation (Ethical) 
Only document persistence risks - never deploy real payloads. Suggest defensive hardening and provide mitigation examples.15. Reporting & Recommendations
Rate findings as Critical / High / Medium / Low.Include:
- Reproduction summary
- Impact analysis
- Screenshots/logs
- Fix recommendations and re-test steps
16. Hardening Checklist 
- Use least-privilege ACLs
- Code-sign all binaries
- Secure TLS connections
- Remove unsafe serializers
- Implement input validation everywhere
17. Essential Tools 
Sysinternals Suite • Wireshark • Fiddler • Burp Suite • Ghidra • dnSpy • IDA • x64dbg • Frida • AFL/boofuzz18. Example Case 
App: SecureNotes.exe
Hardcoded AES key in resources- Notes database world-readable
- Named pipe without ACLs
Fix: derive keys from user passwords, secure file/pipe permissions, validate IPC callers
19. Reporting Template 
- Title & severity
- Affected component/version
- Impact summary
- Steps to reproduce (overview)
- Evidence (logs/screenshots)
- Fix recommendation
- Verification results
In summary:
This cheat sheet helps ethical hackers perform full Windows app pentests - from static and dynamic analysis to fuzzing, crypto testing, and secure reporting. Use it to strengthen defenses, not to exploit vulnerabilities.