4.3 KiB
Laika
Laika is a simple Remote Access Toolkit stack for educational purposes. It allows authenticated communication across a custom protocol with generated key pairs which are embedded into the executable (only the public key is embedded in the bot client ofc). The bot client supports both Windows & Linux environments, while the shell & CNC server specifically target Linux environments.
Some notable features thus far:
- Lightweight, the bot alone is 270kb (22kb if not statically linked with LibSodium) and uses very little resources minimizing Laika's footprint.
- Authentication & packet encryption using LibSodium and a predetermined public CNC key.
- Ability to open shells remotely on the victim's machine.
- Ability to relay socket connections to/from the victim's machine.
- Uses obfuscation techniques also seen in the wild (string obfuscation, tiny VMs executing sensitive operations, etc.)
- Simple configuration using CMake
- Setting keypairs (
-DLAIKA_PUBKEY=? -DLAIKA_PRIVKEY=?
, etc.) - Obfuscation modes
- Setting keypairs (
Would this work in real world scenarios?
My hope is that this becomes complete enough to be accurate to real RAT sources seen in the wild. However since Laika uses a binary protocol, the traffic the bot/CNC create would look very suspect and scream to sysadmins. This is why most RATs/botnets nowadays use an HTTP-based protocol, not only to 'blend in' with traffic, but it also scales well with large networks of bots where the CNC can be deployed across multiple servers and have a generic HTTP load balancer.
I could add some padding to each packet to make it look pseudo-HTTP-like, however I haven't given much thought to this.
Directories explained
/cmake-modules
holds helper functions for CMake./lib
is a shared static library between the bot, shell & CNC. LibSodium is also vendor'd here./cnc
is the Command aNd Control server. (Currently only targets Linux)/bot
is the bot client to be ran on the target machine. (Targets both Linux and Windows)/shell
is the main shell to connect to the CNC server with to issue commands. (Currently only targets Linux)/tools
holds tools for generating keypairs, etc.
CMake Definitions
Definition | Description | Example |
---|---|---|
LAIKA_PUBKEY | Sets CNC's public key | -DLAIKA_PUBKEY=997d026d1c65deb6c30468525132be4ea44116d6f194c142347b67ee73d18814 |
LAIKA_PRIVKEY | Sets CNC's private key | -DLAIKA_PRIVKEY=1dbd33962f1e170d1e745c6d3e19175049b5616822fac2fa3535d7477957a841 |
LAIKA_CNC_IP | Sets CNC's public ip | -DLAIKA_CNC_IP=127.0.0.1 |
LAIKA_CNC_PORT | Sets CNC's bind()'d port | -DLAIKA_CNC_PORT=13337 |
examples are passed to
cmake -B <dir>
Configuration and compilation
Make sure you have the following libraries and tools installed:
- CMake (>=3.10)
- Compiler with C11 support (GCC >= 4.7, Clang >= 3.1, etc.)
The only dependency (LibSodium) is vender'd and statically compiled against the /lib
. This should be kept up-to-date against stable and security related updates to LibSodium.
First, compile the target normally
$ cmake -B build && cmake --build build
Now, generate your custom key pair using genKey
$ ./bin/genKey
Next, rerun cmake, but passing your public and private keypairs
$ rm -rf build &&\
cmake -B build -DLAIKA_PUBKEY=997d026d1c65deb6c30468525132be4ea44116d6f194c142347b67ee73d18814 -DLAIKA_PRIVKEY=1dbd33962f1e170d1e745c6d3e19175049b5616822fac2fa3535d7477957a841 -DCMAKE_BUILD_TYPE=MinSizeRel &&\
cmake --build build
Output binaries are put in the ./bin
folder