{"id":2955,"library":"frida","title":"Frida","description":"Frida is a dynamic instrumentation toolkit for developers, reverse-engineers, and security researchers. It allows injecting custom scripts into processes on various platforms (Windows, macOS, Linux, Android, iOS, tvOS, watchOS, QNX, etc.) to inspect, modify, and trace their behavior at runtime. The current Python binding version is 17.9.1, and it maintains a rapid release cadence with frequent updates.","status":"active","version":"17.9.1","language":"en","source_language":"en","source_url":"https://github.com/frida/frida","tags":["reverse-engineering","security","dynamic-instrumentation","debugging","hooking","runtime-analysis"],"install":[{"cmd":"pip install frida","lang":"bash","label":"Install Frida Python library"},{"cmd":"pip install frida-tools","lang":"bash","label":"Install Frida CLI tools (recommended alongside)"}],"dependencies":[],"imports":[{"symbol":"frida","correct":"import frida"},{"note":"Device objects are typically obtained through discovery methods like `frida.get_local_device()`, `frida.get_usb_device()`, or `frida.get_remote_device()`, not directly imported.","symbol":"Device","correct":"frida.get_local_device()"},{"note":"Session objects are returned by `device.attach()` or `device.spawn()` methods, not directly imported.","symbol":"Session","correct":"device.attach(pid)"},{"note":"Script objects are created via `session.create_script()` and loaded to execute JavaScript. Older versions might have used `frida.core.Script` for direct instantiation, which is less common for typical use cases now.","symbol":"Script","correct":"session.create_script(source)"}],"quickstart":{"code":"import frida\nimport sys\nimport os\nimport time\n\ndef on_message(message, data):\n    print(f\"[+] Message from script: {message}, data: {data}\")\n\ntry:\n    # Define a target process. On Windows, try 'notepad.exe'. On Unix-like, try 'bash' or 'sleep 60'.\n    # You can set this via an environment variable or change it directly.\n    # Example: FRIDA_TARGET_PROCESS=bash python your_script.py\n    process_name = os.environ.get('FRIDA_TARGET_PROCESS', 'notepad.exe' if sys.platform == 'win32' else 'bash')\n\n    print(f\"[*] Attempting to attach to process: {process_name}\")\n    session = None\n    try:\n        session = frida.attach(process_name)\n        print(f\"[*] Attached to {session.pid}\")\n    except frida.ProcessNotFoundError:\n        print(f\"[-] Process '{process_name}' not found. Trying to spawn it.\")\n        # Spawning might require specific paths or arguments for the process.\n        if sys.platform == 'win32':\n            spawn_cmd = [process_name] # For notepad.exe\n        else:\n            # For bash, spawn it with a command that keeps it alive for a bit\n            spawn_cmd = [process_name, '-c', 'sleep 60 & exec bash'] # or ['sleep', '60']\n\n        pid = frida.spawn(spawn_cmd)\n        session = frida.attach(pid)\n        print(f\"[*] Spawned PID: {pid}. Attached.\")\n        # Resume the spawned process if it was suspended (default for frida.spawn)\n        frida.resume(pid)\n        time.sleep(1) # Give it a moment to stabilize after resume\n\n    script_source = \"\"\"\n    // Example JavaScript payload: Intercept a file opening function.\n    // Note: 'open' is common on Unix-like. On Windows, 'CreateFileW' is often used.\n    \n    var targetFunction = null;\n    if (Process.platform === 'windows') {\n        targetFunction = Module.findExportByName('kernel32.dll', 'CreateFileW');\n        if (targetFunction) {\n            Interceptor.attach(targetFunction, {\n                onEnter: function(args) {\n                    this.filename = Memory.readUtf16String(args[0]);\n                    console.log('[JS] CreateFileW() called with filename: ' + this.filename);\n                },\n                onLeave: function(retval) {\n                    // console.log('[JS] CreateFileW() returned: ' + retval);\n                }\n            });\n            console.log('[JS] Frida script for CreateFileW loaded!');\n        } else {\n            console.log('[JS] CreateFileW not found in kernel32.dll');\n        }\n    } else {\n        targetFunction = Module.findExportByName(null, 'open');\n        if (targetFunction) {\n            Interceptor.attach(targetFunction, {\n                onEnter: function(args) {\n                    this.path = Memory.readUtf8String(args[0]);\n                    console.log('[JS] open() called with path: ' + this.path);\n                },\n                onLeave: function(retval) {\n                    // console.log('[JS] open() returned: ' + retval);\n                }\n            });\n            console.log('[JS] Frida script for open() loaded!');\n        } else {\n            console.log('[JS] open not found.');\n        }\n    }\n    console.log('[JS] Frida script initialization complete!');\n    \"\"\"\n\n    script = session.create_script(script_source)\n    script.on('message', on_message) # Attach a Python callback for messages from the JS script\n    script.load() # Inject and execute the JavaScript\n\n    print(\"[+] Script loaded. Intercepting calls. Press Enter to detach and exit...\")\n    sys.stdin.read() # Keep the Python script alive to allow interaction\n\nexcept frida.core.RPCException as e:\n    print(f\"[-] Frida RPC Error: {e}\")\n    if \"Unable to connect\" in str(e) or \"Failed to attach\" in str(e):\n        print(\"    Hint: Ensure 'frida-server' is running on the target device/host, or that you have sufficient permissions.\")\n    elif \"Process not found\" in str(e):\n        print(\"    Hint: The target process might not be running or the name is incorrect.\")\nexcept Exception as e:\n    print(f\"[-] An unexpected error occurred: {e}\")\nfinally:\n    if session:\n        print(\"[*] Detaching from process...\")\n        session.detach()\n    print(\"[*] Exited.\")\n","lang":"python","description":"This quickstart demonstrates how to attach to an existing process or spawn a new one, inject a basic JavaScript payload to intercept file opening calls, and receive messages from the injected script. It includes platform-specific adjustments for Windows vs. Unix-like systems and error handling for common Frida issues. Ensure `frida-server` is running on a remote target if not working locally."},"warnings":[{"fix":"Ensure `pip install frida` and `frida-server` (on the target) are of the exact same version. Use `frida --version` and `frida-server --version` to verify. If using `frida-tools`, it should also match.","message":"The `frida` Python package version MUST precisely match the version of `frida-server` running on the target device/host. A version mismatch (even minor versions like 17.0.x vs 17.2.x) is the most frequent cause of 'Unable to connect', 'Failed to inject', or 'Lost connection' errors.","severity":"breaking","affected_versions":"All versions, especially across major/minor boundaries."},{"fix":"Run your Python script or `frida-server` with `sudo` (Linux/macOS) or as Administrator (Windows). Be aware of security implications.","message":"Frida operations often require elevated privileges. Attaching to system processes, processes owned by other users, or performing certain injections typically requires root/administrator permissions. Running without sufficient privileges will result in 'access denied' or 'permission denied' errors.","severity":"gotcha","affected_versions":"All versions."},{"fix":"Always consult the official Frida release notes (`github.com/frida/frida/releases`) and Python API documentation (`frida.re/docs/py/`) when upgrading to a new major version to identify and adapt to breaking changes.","message":"Major `frida` versions (e.g., from 16.x to 17.x) frequently introduce breaking changes to both the Python API and the underlying JavaScript (GumJS) API. This can lead to scripts failing or behaving unexpectedly after an upgrade.","severity":"breaking","affected_versions":"Major version bumps (e.g., >16.x)."},{"fix":"After `script.load()`, ensure your Python script has a blocking call (e.g., `sys.stdin.read()` for user input, or an event loop that processes messages) to prevent premature termination of the Frida session. Implement proper `finally` blocks for `session.detach()`.","message":"When injecting a JavaScript script, the Python host script must keep the `session` alive for the JavaScript to continue executing. If the Python script exits or `session.detach()` is called prematurely, the injected script will stop. For long-running monitoring, use `sys.stdin.read()` or block indefinitely waiting for messages.","severity":"gotcha","affected_versions":"All versions."}],"env_vars":null,"last_verified":"2026-04-11T00:00:00.000Z","next_check":"2026-07-10T00:00:00.000Z"}