Executes a binary or file in memory on a Linux system. Uses the memfd_create(2) syscall. Credits and idea from: https://magisterquis.github.io/2018/03/31/in-memory-only-elf-execution.html

invokeInMemLinux.go

package main

import (
	"io/ioutil"
	"os"
	"os/exec"
	"strconv"
	"syscall"
	"unsafe"
)

func main() {
	newFdName := "test_fd"
	fdName, err := syscall.BytePtrFromString(newFdName)
	if err != nil {
		panic(err)
	}
	fd, _, _ := syscall.Syscall(319, uintptr(unsafe.Pointer(fdName)), 1, 0)

	pid := os.Getpid()

	file, err := ioutil.ReadFile("/home/capnspacehook/test.bin")
	if err != nil {
		panic(err)
	}

	fdPath := "/proc/" + strconv.Itoa(pid) + "/fd/" + strconv.Itoa(int(fd))
	err = ioutil.WriteFile(fdPath, file, 0755)
	if err != nil {
		panic(err)
	}
	println(fdPath)

	fdCmd := exec.Command(fdPath)
	fdCmd.Stdout = os.Stdout
	fdCmd.Stderr = os.Stderr
	err = fdCmd.Run()
	if err != nil {
		panic(err)
	}
}