VBA and P-code
I want to draw your attention to some great work Dr. Bontchev did.
pcodedmp.py is a VBA P-code disassembler. Microsoft Office documents contain VBA macros in several forms. They contain the source code, but also compiled P-code. Dr. Bontchev created a proof-of-concept document that executes P-code and does not contain the corresponding source code. Here is the output from his pcodedmp.py tool for his PoC document:
python pcodedmp.py -d poc2b.doc
Processing file: poc2b.doc
===============================================================================
Module streams:
Macros/VBA/ThisDocument - 1949 bytes
Line #0:
FuncDefn (Sub / Property Set) func_00000078
Line #1:
LitStr 0x001D "This could have been a virus!"
Ld vbInformation
Ld vbOKOnly
Add
LitStr 0x0006 "Virus!"
ArgsCall MsgBox 0x0003
Line #2:
LitStr 0x0008 "calc.exe"
Paren
ArgsCall Shell 0x0001
Line #3:
EndSub
Dr. Bontchev also coded a plugin for oledump.
Didier Stevens
Microsoft MVP Consumer Security
blog.DidierStevens.com DidierStevensLabs.com
Comments
Anonymous
Sep 27th 2016
8 years ago
Anonymous
Sep 27th 2016
8 years ago
Anonymous
Sep 27th 2016
8 years ago