Thick Client Pentesting Checklist

OWASP Based Checklist by Hariprasaanth R

Also available on Notion \

INFORMATION GATHERING

Information Gathering

• Find out the application architecture (two-tier or three-tier)

• Find out the technologies used (languages and frameworks)

• Identify network communication

• Observe the application process

• Observe each functionality and behavior of the application

• Identify all the entry points

• Analyze the security mechanism (authorization and authentication)

Tools Used

• CFF Explorer

• Sysinternals Suite

• Wireshark

• PEid

• Detect It Easy (DIE)

• Strings

GUI TESTING

Test For GUI Object Permission

• Display hidden form object

• Try to activate disabled functionalities

• Try to uncover the masked password

Test GUI Content

• Look for sensitive information

Test For GUI Logic

• Try for access control and injection-based vulnerabilities

• Bypass controls by utilizing intended GUI functionality

• Check improper error handling

• Check weak input sanitization

• Try privilege escalation (unlocking admin features to normal users)

• Try payment manipulation

Tools Used

• UISpy

• Winspy++

• Window Detective

• Snoop WPF

FILE TESTING

Test For Files Permission

• Check permission for each and every file and folder

Test For File Continuity

• Check strong naming

• Authenticate code signing

Test For File Content Debugging

• Look for sensitive information on the file system (symbols, sensitive data, passwords, configurations)

• Look for sensitive information on the config file

• Look for Hardcoded encryption data

• Look for Clear text storage of sensitive data

• Look for side-channel data leakage

• Look for unreliable log

Test For File And Content Manipulation

• Try framework backdooring

• Try DLL preloading

• Perform Race condition check

• Test for Files and content replacement

• Test for Client-side protection bypass using reverse engineering

Test For Function Exported

• Try to find the exported functions

• Try to use the exported functions without authentication

Test For Public Methods

• Make a wrapper to gain access to public methods without authentication

Test For Decompile And Application Rebuild

• Try to recover the original source code, passwords, keys

• Try to decompile the application

• Try to rebuild the application

• Try to patch the application

Test For Decryption And DE obfuscation

• Try to recover original source code

• Try to retrieve passwords and keys

• Test for lack of obfuscation

Test For Disassemble and Reassemble

• Try to build a patched assembly

Tools Used

• Strings

• dnSpy

• Procmon

• Process Explorer

• Process Hacker

REGISTRY TESTING

Test For Registry Permissions

• Check read access to the registry keys

• Check to write access to the registry keys

Test For Registry Contents

• Inspect the registry contents

• Check for sensitive info stored on the registry

• Compare the registry before and after executing the application

Test For Registry Manipulation

• Try for registry manipulation

• Try to bypass authentication by registry manipulation

• Try to bypass authorization by registry manipulation

Tools Used

• Regshot

• Procmon

• Accessenum

NETWORK TESTING

Test For Network

• Check for sensitive data in transit

• Try to bypass firewall rules

• Try to manipulate network traffic

Tools Used

• Wireshark

• TCPview

ASSEMBLY TESTING

Test For Assembly

• Verify Address Space Layout Randomization (ASLR)

• Verify SafeSEH

• Verify Data Execution Prevention (DEP)

• Verify strong naming

• Verify ControlFlowGuard

• Verify HighentropyVA

Tools Used

• PESecurity

MEMORY TESTING

Test For Memory Content

• Check for sensitive data stored in memory

Test For Memory Manipulation

• Try for memory manipulation

• Try to bypass authentication by memory manipulation

• Try to bypass authorization by memory manipulation

Test For Run Time Manipulation

• Try to analyze the dump file

• Check for process replacement

• Check for modifying assembly in the memory

• Try to debug the application

• Try to identify dangerous functions

• Use breakpoints to test each and every functionality

Tools Used

• Process Hacker

• HxD

• Strings

TRAFFIC TESTING

Test For Traffic

• Analyze the flow of network traffic

• Try to find sensitive data in transit

Tools Used

• Echo Mirage

• MITM Relay

• Burp Suite

COMMON VULNERABILITIES TESTING

Test For Common Vulnerabilities

• Try to decompile the application

• Try for reverse engineering

• Try to test with OWASP WEB Top 10

• Try to test with OWASP API Top 10

• Test for DLL Hijacking

• Test for signature checks (Use Sigcheck)

• Test for binary analysis (Use Binscope)

• Test for business logic errors

• Test for TCP/UDP attacks

• Test with automated scanning tools (Use Visual Code Grepper - VCG)