Cross Compiling Implants

NOTE: Any platform can cross-compile a standalone executable to any other platform out of the box, you only need cross-compilers when using --format shared.

Sliver can tell you which platforms it can likely target based on the server's platform and available cross-compilers by running the generate info command in the console.

Sliver v1.5.30 and later also support External Builders, which can be used to easily cross-compile implants.

From Linux to MacOS/Windows

To compile Windows shared library and shellcode implants from Linux, install mingw from your local package manager:

sudo apt install mingw-w64

To compile MacOS shared library implants from Linux, we recommend using https://github.com/tpoechtrager/osxcross by default Sliver will look in /opt/osxcross but you can override this via environment variables. If you do not have a MacOS based machine you can use GitHub Actions' MacOS instances to build OSXCross.

NOTE: Sliver expects the root of the osxcross git repo to be located at /opt/osxcross and the actual binaries in /opt/osxcross/target/bin.

An example deployment is shown below, you have to procure the MacOSX11.1.sdk.tar.xz yourself due to license restrictions (see the OSXCross GitHub for more details):

sudo apt-get install -y git curl libssl-dev cmake liblzma-dev libxml2-dev patch clang zlib1g-dev
git clone https://github.com/tpoechtrager/osxcross.git /opt/osxcross
curl -o /opt/osxcross/tarballs/MacOSX11.1.sdk.tar.xz 'https://example.com/MacOSX11.1.sdk.tar.xz'
cd /opt/osxcross
UNATTENDED=1 ./build.sh

Sliver automatically looks in the default paths for these cross compilers, once installed simply use the generate command with the desired --os and --arch, check ~/.sliver/logs/sliver.log for build errors. You can override any cross compiler location via the appropriate environment variables.

From MacOS to Linux/Windows

To compile Windows shared library and shellcode implants from MacOS install mingw from brew:

brew install mingw-w64

For Linux, we recommend musl-cross to target 64-bit Linux, which can be installed via brew:

brew install FiloSottile/musl-cross/musl-cross
brew install mingw-w64

I'm not aware of any good options to target 32-bit Linux from MacOS. Sliver automatically looks in the default paths for these cross compilers, once installed simply use the generate command with the desired --os and --arch, check ~/.sliver/logs/sliver.log for build errors. You can override any cross compiler location via the appropriate environment variables.

From Windows to MacOS/Linux

Good luck.