Advanced malware analysis training session5 reversing automation
- 2. Disclaimer The Content, Demonstration, Source Code and Programs presented here is "AS IS" without any warranty or conditions of any kind. Also the views/ideas/knowledge expressed here are solely of the trainer’s only and nothing to do with the company or the organization in which the trainer is currently working. However in no circumstances neither the Trainer nor Cysinfo is responsible for any damage or loss caused due to use or misuse of the information presented here.
- 3. Acknowledgement Special thanks to Null community for their extended support and co-operation. Special thanks to ThoughtWorks for the beautiful venue. Thanks to all the trainers who have devoted their precious time and countless hours to make it happen.
- 4. Advanced Malware Analysis Training This presentation is part of our Advanced Malware Analysis Training program. Currently it is delivered only during our local meets for FREE of cost.
- 5. Who am I? Harsimran Walia Member, SecurityXploded Research Scientist, McAfee Labs Reversing, Malware Analysis, Exploit Analysis/Development etc. Personal site: http://harsimranwalia.info E-mail: [email protected] Twitter: b44nz0r
- 6. Automation ◦ Python scripts ◦ Use of modules Tools/Modules discussed ◦ PEfile ◦ PyDbg ◦ IDAPython
- 7. Python module to read and work with Portable Executable (PE) files pefile requires understanding of the layout of a PE file (already covered) Tasks that pefile makes possible are: ◦ Modifying and writing back to the PE image ◦ Header Inspection ◦ Sections analysis ◦ Retrieving data ◦ Warnings for suspicious and malformed values ◦ Packer detection with PEiD’s signatures
- 8. Load a PE (create an instance) Reading important PE header attributes Modifying values All PE instance values support assignment followed by a call to write function to write the modified exe to system
- 9. PE sections – fetching detail about sections File Info Output Output
- 10. Type of file (exe/dll/driver) List of imported dlls and imported functions
- 11. Open Source Python debugger Developed by Pedram Amini as the main component of PaiMei framework It uses user-defined callback functions These functions can implement actions to take on hitting a breakpoint, exception etc Upon execution of the callback function the control is passed back to pydbg to execute the program normally
- 12. Download or git clone: https://github.com/OpenRCE/pydbg Pre-reqs ◦ Python 2.7 ◦ c-types python library Copy the pydbg files to Python-2.7Libsite- packagespydbg pydasm.pyd is compiled for Python 2.6, lets fix this! Open pydasm.pyd in any hex-editor(010 etc) and search python ◦ Change python26.dll to python27.dll ◦ Save and replace with original
- 13. Import required pydbg modules and struct • Look for process to debug • Attach debugger to process • Set breakpoint on function entry address • Attach a breakpoint handler Breakpoint handler for CreateFileA Extract the parameter from the stack = filename Breakpoint handler for CreateFileW
- 14. An IDA Pro plugin Integrates Python, allowing scripts to run in IDA Pro IDAPython Scripts have access to ◦ IDA Plugin API, ◦ IDC and all modules available for Python
- 15. Download the plugin from https://code.google.com/p/idapython Match the IDAPro and python version before downloading Copy the ''python'' directory from the extracted plugin to the IDA Pro install directory (%IDADIR%) Copy the plugin executable to ''%IDADIR%plugins''
- 16. Utility functions ◦ ScreenEA() Obtains the address of where your cursor is currently positioned on the IDA screen. ◦ GetInputFileMD5() Returns the MD5 hash of the binary loaded in IDA, which is useful for tracking changes in the binary Functions ◦ Functions( long StartAddress, long EndAddress ) Returns a list of all function start addresses contained between StartAddress and EndAddress. ◦ LocByName( string FunctionName ) Returns the address of a function based on its name. ◦ GetFunctionName( long Address ) Given an address, returns the name of the function the address belongs to.
- 17. Try running on war-ftpd.exe
- 19. Thank You !