mildsunrise/redasm-abc

🕵️ Easy-to-use, simple assistant for SWF disassembly.

Robust, Easy [Dis-]Assembler for ActionScript Bytecode

redasm-abc provides an easy and simple SWF reverse-engineering workflow using the excellent RABCDAsm assembler. Demo here.

Installation

You need a working D compiler to build redasm-abc. It's recommended you install liblzma and its development files, otherwise redasm won't be able to handle LZMA-compressed SWFs.

To build:

$ git submodule update --init
$ rdmd build_redasm.d

If it succeeds, copy the resulting executable to your PATH:

$ sudo install redasm /usr/local/bin

That's it! You should now be able to do redasm from anywhere.

Usage

Put the SWF you want to inspect in an empty directory.
Then run redasm to extract all its ABC blocks and disassemble them.
Edit what you want, then run redasm again to apply the changes to the SWF.

redasm-abc will create a directory for each disassembled ABC block (block-0, block-1, block-2) where its dissassembly lives. Never rename the directories themselves, nor modify the SWF yourself. This will confuse redasm-abc.

Tips

Just after running redasm on an SWF, you should immediately add the files to i.e. Git, even if you're just planning to read the assembly.

redasm
git init && git add -A
git commit -m "disassemble SWF"

Also read the tips on RABCDAsm itself.

Before disassembling an SWF for the first time, redasm creates a backup of the SWF ending in .bak, at the same directory.