Merge branch 'main' into add-shell-completion-command

README.md

@@ -60,6 +60,28 @@ For alternative installation options and known issues, please refer to the [docu
 
 MVT provides two commands `mvt-ios` and `mvt-android`. [Check out the documentation to learn how to use them!](https://docs.mvt.re/)
 
+### Shell completion
+
+MVT can generate shell completion scripts for Bash, Zsh, and Fish:
+
+```bash
+mvt-ios completion
+mvt-android completion
+```
+
+The commands print setup instructions by default. To generate a completion script directly, pass the shell name:
+
+```bash
+mvt-ios completion bash
+mvt-android completion zsh
+```
+
+MVT only writes completion files or shell configuration when `--install` is passed. See the [command completion documentation](https://docs.mvt.re/en/latest/command_completion/) for details.
+Module-running `check-*` commands can load custom Python modules with
+`--load-module PATH` or from a folder set in `MVT_CUSTOM_MODULES`. See the
+[development documentation](https://docs.mvt.re/en/latest/development/) for
+details.
+
 
 ## License
 

docs/command_completion.md

@@ -4,7 +4,7 @@ MVT utilizes the [Click](https://click.palletsprojects.com/en/stable/) library f
 
 Click provides tab completion support for Bash (version 4.4 and up), Zsh, and Fish.
 
-To enable it, you need to manually register a special function with your shell, which varies depending on the shell you are using.
+To enable it, you need to register a completion script with your shell, which varies depending on the shell you are using.
 
 The following describes how to generate the command completion scripts and add them to your shell configuration.
 
@@ -13,31 +13,54 @@ The following describes how to generate the command completion scripts and add t
 ### For Bash
 
 ```bash
-# Generates bash completion scripts
+# Generate bash completion scripts
-echo "$(_MVT_IOS_COMPLETE=bash_source mvt-ios)" > ~/.mvt-ios-complete.bash &&
+mvt-ios completion bash > ~/.mvt-ios-complete.bash
-echo "$(_MVT_ANDROID_COMPLETE=bash_source mvt-android)" > ~/.mvt-android-complete.bash
+mvt-android completion bash > ~/.mvt-android-complete.bash
 ```
 
 Add the following to `~/.bashrc`:
 ```bash
 # source mvt completion scripts
-. ~/.mvt-ios-complete.bash && .  ~/.mvt-android-complete.bash
+[ -f ~/.mvt-ios-complete.bash ] && . ~/.mvt-ios-complete.bash
+[ -f ~/.mvt-android-complete.bash ] && . ~/.mvt-android-complete.bash
 ```
 
 ### For Zsh
 
 ```bash
-# Generates zsh completion scripts
+# Generate zsh completion scripts
-echo "$(_MVT_IOS_COMPLETE=zsh_source mvt-ios)" >  ~/.mvt-ios-complete.zsh &&
+mvt-ios completion zsh > ~/.mvt-ios-complete.zsh
-echo "$(_MVT_ANDROID_COMPLETE=zsh_source mvt-android)" > ~/.mvt-android-complete.zsh
+mvt-android completion zsh > ~/.mvt-android-complete.zsh
 ```
 
 Add the following to `~/.zshrc`:
 ```bash
 # source mvt completion scripts
-.  ~/.mvt-ios-complete.zsh  && .  ~/.mvt-android-complete.zsh
+[ -f ~/.mvt-ios-complete.zsh ] && . ~/.mvt-ios-complete.zsh
+[ -f ~/.mvt-android-complete.zsh ] && . ~/.mvt-android-complete.zsh
 ```
 
+### For Fish
+
+```bash
+# Generate fish completion scripts
+mkdir -p ~/.config/fish/completions
+mvt-ios completion fish > ~/.config/fish/completions/mvt-ios.fish
+mvt-android completion fish > ~/.config/fish/completions/mvt-android.fish
+```
+
+Fish loads completion files from `~/.config/fish/completions` automatically.
+
+### Automatic Installation
+
+MVT can write the completion file and update the relevant shell configuration for Bash and Zsh when you pass `--install`:
+
+```bash
+mvt-ios completion bash --install
+mvt-android completion bash --install
+```
+
+Replace `bash` with `zsh` or `fish` as needed. For Fish, `--install` writes the completion file into `~/.config/fish/completions`.
+
 For more information, visit the official [Click Docs](https://click.palletsprojects.com/en/stable/shell-completion/#enabling-completion).
 
-

docs/development.md

@@ -39,6 +39,82 @@ Selecting a single module also runs its transitive dependencies. If a dependency
 is unavailable or the dependency graph contains a cycle, the command logs a
 warning and does not run any modules.
 
+## Custom modules
+
+Module-running `check-*` commands can load custom modules from Python files that
+are not installed as part of MVT. Load one file with:
+
+```bash
+mvt-ios check-backup --load-module ./example_module.py --output ./out ./backup
+```
+
+You can also load a folder. MVT loads non-hidden top-level `*.py` files in
+sorted order and skips `__init__.py`:
+
+```bash
+mvt-ios check-fs --load-module ./custom_modules ./filesystem-dump
+```
+
+Set `MVT_CUSTOM_MODULES` to load a folder for every module-running command. This
+folder is loaded before any `--load-module` path:
+
+```bash
+MVT_CUSTOM_MODULES=./custom_modules mvt-android check-bugreport ./bugreport.zip
+```
+
+Custom modules are normal `MVTModule` subclasses:
+
+```python
+from mvt.common.module import MVTModule
+
+
+class ExampleCustomModule(MVTModule):
+    supported_commands = (("ios", "check-backup"), ("ios", "check-fs"))
+    slug = "example_custom_module"
+
+    def run(self):
+        self.results = [{"message": "custom module ran"}]
+
+    def check_indicators(self):
+        pass
+
+    def serialize(self, result):
+        return None
+```
+
+Use `supported_commands` to restrict a module to specific platform/command
+pairs. Missing or empty `supported_commands` means the module is available to
+all commands, which keeps older modules compatible. Supported pairs are:
+
+```python
+("ios", "check-backup")
+("ios", "check-fs")
+("ios", "check-iocs")
+("android", "check-backup")
+("android", "check-bugreport")
+("android", "check-androidqf")
+("android", "check-intrusion-logs")
+("android", "check-iocs")
+```
+
+Custom modules can depend on existing MVT module classes. Dependencies are
+resolved with the same ordering logic as built-in modules, and custom modules
+are appended after built-ins before ordering:
+
+```python
+from mvt.common.module import MVTModule
+from mvt.ios.modules.backup.manifest import Manifest
+
+
+class DependentCustomModule(MVTModule):
+    supported_commands = (("ios", "check-backup"),)
+    dependencies = (Manifest,)
+
+    def run(self):
+        manifest_results = self.get_dependency_results(Manifest)
+        self.results = [{"manifest_entries": len(manifest_results)}]
+```
+
 ## Profiling
 
 Some MVT modules extract and process significant amounts of data during the analysis process or while checking results against known indicators. Care must be

src/mvt/android/cli.py

@@ -8,6 +8,12 @@ import logging
 import click
 
 from mvt.common.cmd_check_iocs import CmdCheckIOCS
+from mvt.common.completion import (
+    SUPPORTED_SHELLS,
+    completion_instructions,
+    generate_completion_script,
+    install_completion_script,
+)
 from mvt.common.help import (
     HELP_MSG_ANDROID_BACKUP_PASSWORD,
     HELP_MSG_CHECK_ADB_REMOVED,
@@ -17,11 +23,13 @@ from mvt.common.help import (
     HELP_MSG_CHECK_BUGREPORT,
     HELP_MSG_CHECK_IOCS,
     HELP_MSG_CHECK_INTRUSION_LOGS,
+    HELP_MSG_COMPLETION,
     HELP_MSG_DISABLE_INDICATOR_UPDATE_CHECK,
     HELP_MSG_DISABLE_UPDATE_CHECK,
     HELP_MSG_HASHES,
     HELP_MSG_IOC,
     HELP_MSG_LIST_MODULES,
+    HELP_MSG_LOAD_MODULE,
     HELP_MSG_MODULE,
     HELP_MSG_NONINTERACTIVE,
     HELP_MSG_OUTPUT,
@@ -30,6 +38,7 @@ from mvt.common.help import (
     HELP_MSG_VERSION,
 )
 from mvt.common.logo import logo
+from mvt.common.module_loader import CustomModuleLoadError, load_custom_modules
 from mvt.common.updates import IndicatorsUpdates
 from mvt.common.utils import init_logging, set_verbose_logging
 
@@ -59,6 +68,13 @@ def _get_disable_flags(ctx):
     )
 
 
+def _load_custom_modules(load_module):
+    try:
+        return load_custom_modules(load_module)
+    except CustomModuleLoadError as exc:
+        raise click.ClickException(str(exc)) from exc
+
+
 # ==============================================================================
 # Main
 # ==============================================================================
@@ -76,6 +92,7 @@ def cli(ctx, disable_update_check, disable_indicator_update_check):
     ctx.ensure_object(dict)
     ctx.obj["disable_version_check"] = disable_update_check
     ctx.obj["disable_indicator_check"] = disable_indicator_update_check
+    if ctx.invoked_subcommand != "completion":
         logo(
             disable_version_check=disable_update_check,
             disable_indicator_check=disable_indicator_update_check,
@@ -90,6 +107,40 @@ def version():
     return
 
 
+# ==============================================================================
+# Command: completion
+# ==============================================================================
+@cli.command("completion", context_settings=CONTEXT_SETTINGS, help=HELP_MSG_COMPLETION)
+@click.argument("shell", required=False, type=click.Choice(SUPPORTED_SHELLS))
+@click.option(
+    "--install",
+    is_flag=True,
+    help="Write completion files and update shell configuration.",
+)
+@click.pass_context
+def completion(ctx, shell, install):
+    program_name = "mvt-android"
+
+    if shell is None:
+        if install:
+            raise click.UsageError("A shell is required when using --install.")
+        click.echo(completion_instructions(program_name))
+        return
+
+    root_cli = ctx.find_root().command
+
+    if install:
+        script_path = install_completion_script(root_cli, program_name, shell)
+        click.echo(f"Installed {shell} completion to {script_path}")
+        if shell in ("bash", "zsh"):
+            click.echo(f"Updated ~/.{shell}rc")
+        else:
+            click.echo("Fish loads completion files automatically.")
+        return
+
+    click.echo(generate_completion_script(root_cli, program_name, shell))
+
+
 # ==============================================================================
 # Command: check-adb (removed)
 # ==============================================================================
@@ -119,11 +170,28 @@ def check_adb(ctx):
 @click.option("--output", "-o", type=click.Path(exists=False), help=HELP_MSG_OUTPUT)
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
 @click.option("--module", "-m", help=HELP_MSG_MODULE)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.option("--verbose", "-v", is_flag=True, help=HELP_MSG_VERBOSE)
 @click.argument("BUGREPORT_PATH", type=click.Path(exists=True))
 @click.pass_context
-def check_bugreport(ctx, iocs, output, list_modules, module, verbose, bugreport_path):
+def check_bugreport(
+    ctx,
+    iocs,
+    output,
+    list_modules,
+    module,
+    load_module,
+    verbose,
+    bugreport_path,
+):
     set_verbose_logging(verbose)
+    custom_modules = _load_custom_modules(load_module)
     # Always generate hashes as bug reports are small.
     cmd = CmdAndroidCheckBugreport(
         target_path=bugreport_path,
@@ -133,6 +201,7 @@ def check_bugreport(ctx, iocs, output, list_modules, module, verbose, bugreport_
         hashes=True,
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
     )
 
     if list_modules:
@@ -164,6 +233,13 @@ def check_bugreport(ctx, iocs, output, list_modules, module, verbose, bugreport_
 )
 @click.option("--output", "-o", type=click.Path(exists=False), help=HELP_MSG_OUTPUT)
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.option("--non-interactive", "-n", is_flag=True, help=HELP_MSG_NONINTERACTIVE)
 @click.option("--backup-password", "-p", help=HELP_MSG_ANDROID_BACKUP_PASSWORD)
 @click.option("--verbose", "-v", is_flag=True, help=HELP_MSG_VERBOSE)
@@ -174,12 +250,14 @@ def check_backup(
     iocs,
     output,
     list_modules,
+    load_module,
     non_interactive,
     backup_password,
     verbose,
     backup_path,
 ):
     set_verbose_logging(verbose)
+    custom_modules = _load_custom_modules(load_module)
 
     # Always generate hashes as backups are generally small.
     cmd = CmdAndroidCheckBackup(
@@ -193,6 +271,7 @@ def check_backup(
         },
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
     )
 
     if list_modules:
@@ -223,6 +302,13 @@ def check_backup(
 @click.option("--output", "-o", type=click.Path(exists=False), help=HELP_MSG_OUTPUT)
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
 @click.option("--module", "-m", help=HELP_MSG_MODULE)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.option("--hashes", "-H", is_flag=True, help=HELP_MSG_HASHES)
 @click.option("--non-interactive", "-n", is_flag=True, help=HELP_MSG_NONINTERACTIVE)
 @click.option("--backup-password", "-p", help=HELP_MSG_ANDROID_BACKUP_PASSWORD)
@@ -235,6 +321,7 @@ def check_androidqf(
     output,
     list_modules,
     module,
+    load_module,
     hashes,
     non_interactive,
     backup_password,
@@ -242,6 +329,7 @@ def check_androidqf(
     androidqf_path,
 ):
     set_verbose_logging(verbose)
+    custom_modules = _load_custom_modules(load_module)
 
     cmd = CmdAndroidCheckAndroidQF(
         target_path=androidqf_path,
@@ -255,6 +343,7 @@ def check_androidqf(
         },
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
     )
 
     if list_modules:
@@ -288,6 +377,13 @@ def check_androidqf(
 @click.option("--output", "-o", type=click.Path(exists=False), help=HELP_MSG_OUTPUT)
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
 @click.option("--module", "-m", help=HELP_MSG_MODULE)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.option(
     "--timezone",
     "-t",
@@ -307,11 +403,13 @@ def check_intrusion_logs(
     output,
     list_modules,
     module,
+    load_module,
     timezone,
     verbose,
     logs_path,
 ):
     set_verbose_logging(verbose)
+    custom_modules = _load_custom_modules(load_module)
 
     module_options = {}
     if timezone:
@@ -325,6 +423,7 @@ def check_intrusion_logs(
         module_options=module_options if module_options else None,
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
     )
 
     if list_modules:
@@ -352,15 +451,25 @@ def check_intrusion_logs(
 )
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
 @click.option("--module", "-m", help=HELP_MSG_MODULE)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.argument("FOLDER", type=click.Path(exists=True))
 @click.pass_context
-def check_iocs(ctx, iocs, list_modules, module, folder):
+def check_iocs(ctx, iocs, list_modules, module, load_module, folder):
+    custom_modules = _load_custom_modules(load_module)
     cmd = CmdCheckIOCS(
         target_path=folder,
         ioc_files=iocs,
         module_name=module,
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
+        platform="android",
     )
     cmd.modules = (
         BACKUP_MODULES + BUGREPORT_MODULES + ANDROIDQF_MODULES + INTRUSION_LOGS_MODULES

src/mvt/android/cmd_check_androidqf.py

@@ -17,6 +17,7 @@ from mvt.android.cmd_check_backup import CmdAndroidCheckBackup, InvalidAndroidBa
 from mvt.android.cmd_check_bugreport import CmdAndroidCheckBugreport
 from mvt.common.command import Command
 from mvt.common.indicators import Indicators
+from mvt.common.module import MVTModule
 
 from .modules.androidqf import ANDROIDQF_MODULES
 from .modules.androidqf.base import AndroidQFModule
@@ -50,6 +51,7 @@ class CmdAndroidCheckAndroidQF(Command):
         sub_command: Optional[bool] = False,
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
     ) -> None:
         super().__init__(
             target_path=target_path,
@@ -64,8 +66,10 @@ class CmdAndroidCheckAndroidQF(Command):
             log=log,
             disable_version_check=disable_version_check,
             disable_indicator_check=disable_indicator_check,
+            custom_modules=custom_modules,
         )
 
+        self.platform = "android"
         self.name = "check-androidqf"
         self.modules = ANDROIDQF_MODULES
 
@@ -210,6 +214,7 @@ class CmdAndroidCheckAndroidQF(Command):
                 module_options=self.module_options,
                 hashes=self.hashes,
                 sub_command=True,
+                custom_modules=self.custom_modules,
             )
             cmd.from_zip(bugreport)
             cmd.run()
@@ -239,6 +244,7 @@ class CmdAndroidCheckAndroidQF(Command):
             module_options=self.module_options,
             hashes=self.hashes,
             sub_command=True,
+            custom_modules=self.custom_modules,
         )
         try:
             cmd.from_ab(backup)
@@ -318,6 +324,7 @@ class CmdAndroidCheckAndroidQF(Command):
                 module_options=adv_module_options,
                 hashes=self.hashes,
                 sub_command=True,
+                custom_modules=self.custom_modules,
             )
             cmd.run()
 

src/mvt/android/cmd_check_backup.py

@@ -21,6 +21,7 @@ from mvt.android.parsers.backup import (
 )
 from mvt.common.command import Command
 from mvt.common.indicators import Indicators
+from mvt.common.module import MVTModule
 
 from .modules.backup import BACKUP_MODULES
 
@@ -45,6 +46,7 @@ class CmdAndroidCheckBackup(Command):
         sub_command: Optional[bool] = False,
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
     ) -> None:
         super().__init__(
             target_path=target_path,
@@ -59,8 +61,10 @@ class CmdAndroidCheckBackup(Command):
             log=log,
             disable_version_check=disable_version_check,
             disable_indicator_check=disable_indicator_check,
+            custom_modules=custom_modules,
         )
 
+        self.platform = "android"
         self.name = "check-backup"
         self.modules = BACKUP_MODULES
 

src/mvt/android/cmd_check_bugreport.py

@@ -12,6 +12,7 @@ from zipfile import ZipFile
 from mvt.android.modules.bugreport.base import BugReportModule
 from mvt.common.command import Command
 from mvt.common.indicators import Indicators
+from mvt.common.module import MVTModule
 
 from .modules.bugreport import BUGREPORT_MODULES
 
@@ -32,6 +33,7 @@ class CmdAndroidCheckBugreport(Command):
         sub_command: Optional[bool] = False,
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
     ) -> None:
         super().__init__(
             target_path=target_path,
@@ -46,8 +48,10 @@ class CmdAndroidCheckBugreport(Command):
             log=log,
             disable_version_check=disable_version_check,
             disable_indicator_check=disable_indicator_check,
+            custom_modules=custom_modules,
         )
 
+        self.platform = "android"
         self.name = "check-bugreport"
         self.modules = BUGREPORT_MODULES
 

src/mvt/android/cmd_check_intrusion_logs.py

@@ -9,6 +9,7 @@ from typing import Optional
 
 from mvt.common.command import Command
 from mvt.common.indicators import Indicators
+from mvt.common.module import MVTModule
 
 from .modules.intrusion_logs import (
     INTRUSION_LOGS_MODULES,
@@ -35,6 +36,7 @@ class CmdAndroidCheckIntrusionLogs(Command):
         sub_command: Optional[bool] = False,
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
     ) -> None:
         super().__init__(
             target_path=target_path,
@@ -49,8 +51,10 @@ class CmdAndroidCheckIntrusionLogs(Command):
             log=log,
             disable_version_check=disable_version_check,
             disable_indicator_check=disable_indicator_check,
+            custom_modules=custom_modules,
         )
 
+        self.platform = "android"
         self.name = "check-intrusion-logs"
         self.modules = INTRUSION_LOGS_MODULES
         self._all_events: dict[str, list[dict]] = {}

src/mvt/common/cmd_check_iocs.py

@@ -8,6 +8,7 @@ import os
 from typing import Optional
 
 from mvt.common.command import Command
+from mvt.common.module import MVTModule
 from mvt.common.utils import exec_or_profile
 
 log = logging.getLogger(__name__)
@@ -26,6 +27,8 @@ class CmdCheckIOCS(Command):
         sub_command: Optional[bool] = False,
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
+        platform: str = "",
     ) -> None:
         super().__init__(
             target_path=target_path,
@@ -39,14 +42,16 @@ class CmdCheckIOCS(Command):
             log=log,
             disable_version_check=disable_version_check,
             disable_indicator_check=disable_indicator_check,
+            custom_modules=custom_modules,
         )
 
+        self.platform = platform
         self.name = "check-iocs"
 
     def run(self) -> None:
         assert self.target_path is not None
         all_modules = []
-        for entry in self.modules:
+        for entry in self._available_modules():
             if entry not in all_modules:
                 all_modules.append(entry)
 

src/mvt/common/command.py

@@ -19,6 +19,7 @@ from .alerts import AlertLevel, AlertStore
 from .config import settings
 from .indicators import Indicators
 from .module import EncryptedBackupError, MVTModule, run_module, save_timeline
+from .module_loader import module_supports_command
 from .module_types import ModuleTimeline
 from .utils import (
     CustomJSONEncoder,
@@ -44,9 +45,12 @@ class Command:
         log: logging.Logger = logging.getLogger(__name__),
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
     ) -> None:
         self.name = ""
+        self.platform = ""
         self.modules: list[type[MVTModule]] = []
+        self.custom_modules = custom_modules if custom_modules else []
 
         self.target_path = target_path
         self.results_path = results_path
@@ -199,9 +203,24 @@ class Command:
 
     def list_modules(self) -> None:
         self.log.info("Following is the list of available %s modules:", self.name)
-        for module in self.modules:
+        for module in self._available_modules():
             self.log.info(" - %s", module.__name__)
 
+    def _available_modules(self) -> list[type[MVTModule]]:
+        modules = list(self.modules)
+        modules.extend(
+            module
+            for module in self.custom_modules
+            if module_supports_command(module, self.platform, self.name)
+        )
+
+        deduplicated = []
+        for module in modules:
+            if module not in deduplicated:
+                deduplicated.append(module)
+
+        return deduplicated
+
     def init(self) -> None:
         raise NotImplementedError
 
@@ -262,14 +281,15 @@ class Command:
 
     def _ordered_modules(self) -> Optional[list[type[MVTModule]]]:
         """Return enabled modules in stable topological order."""
-        module_indexes = {module: index for index, module in enumerate(self.modules)}
+        modules = self._available_modules()
+        module_indexes = {module: index for index, module in enumerate(modules)}
 
         if self.module_name:
             selected = [
-                module for module in self.modules if module.__name__ == self.module_name
+                module for module in modules if module.__name__ == self.module_name
             ]
         else:
-            selected = [module for module in self.modules if module.enabled]
+            selected = [module for module in modules if module.enabled]
 
         required = set(selected)
         pending = list(selected)

src/mvt/common/completion.py

@@ -0,0 +1,94 @@
+# Mobile Verification Toolkit (MVT)
+# Copyright (c) 2021-2023 The MVT Authors.
+# Use of this software is governed by the MVT License 1.1 that can be found at
+#   https://license.mvt.re/1.1/
+
+from pathlib import Path
+import shlex
+
+import click
+from click.shell_completion import get_completion_class
+
+
+SUPPORTED_SHELLS = ("bash", "zsh", "fish")
+
+
+def completion_instructions(program_name: str) -> str:
+    return f"""Shell completion for {program_name}
+
+Print a completion script:
+  {program_name} completion bash > ~/.{program_name}-complete.bash
+  {program_name} completion zsh > ~/.{program_name}-complete.zsh
+  mkdir -p ~/.config/fish/completions
+  {program_name} completion fish > ~/.config/fish/completions/{program_name}.fish
+
+Load the generated Bash script from ~/.bashrc:
+  [ -f ~/.{program_name}-complete.bash ] && . ~/.{program_name}-complete.bash
+
+Load the generated Zsh script from ~/.zshrc:
+  [ -f ~/.{program_name}-complete.zsh ] && . ~/.{program_name}-complete.zsh
+
+Fish loads completion files from ~/.config/fish/completions automatically.
+
+To write these files and update Bash/Zsh shell configuration automatically:
+  {program_name} completion bash --install
+  {program_name} completion zsh --install
+  {program_name} completion fish --install
+"""
+
+
+def generate_completion_script(cli: click.Command, program_name: str, shell: str) -> str:
+    completion_class = get_completion_class(shell)
+    if completion_class is None:
+        raise click.ClickException(f"Unsupported shell: {shell}")
+
+    complete_var = f"_{program_name.upper().replace('-', '_')}_COMPLETE"
+    return completion_class(cli, {}, program_name, complete_var).source()
+
+
+def install_completion_script(
+    cli: click.Command,
+    program_name: str,
+    shell: str,
+) -> Path:
+    script = generate_completion_script(cli, program_name, shell)
+    script_path = _completion_script_path(program_name, shell)
+    script_path.parent.mkdir(parents=True, exist_ok=True)
+    script_path.write_text(script, encoding="utf-8")
+
+    if shell in ("bash", "zsh"):
+        _install_shell_source_line(program_name, shell, script_path)
+
+    return script_path
+
+
+def _completion_script_path(program_name: str, shell: str) -> Path:
+    home = Path.home()
+
+    if shell == "fish":
+        return home / ".config" / "fish" / "completions" / f"{program_name}.fish"
+
+    return home / f".{program_name}-complete.{shell}"
+
+
+def _install_shell_source_line(program_name: str, shell: str, script_path: Path) -> None:
+    shell_config_path = Path.home() / f".{shell}rc"
+    source_line = (
+        f"[ -f {shlex.quote(str(script_path))} ] && "
+        f". {shlex.quote(str(script_path))}"
+    )
+    block = (
+        f"# MVT shell completion for {program_name}\n"
+        f"{source_line}\n"
+    )
+
+    if shell_config_path.exists():
+        shell_config = shell_config_path.read_text(encoding="utf-8")
+        if source_line in shell_config:
+            return
+    else:
+        shell_config = ""
+
+    separator = "" if not shell_config or shell_config.endswith("\n") else "\n"
+    with shell_config_path.open("a", encoding="utf-8") as handle:
+        handle.write(f"{separator}{block}")

src/mvt/common/help.py

@@ -10,6 +10,10 @@ HELP_MSG_IOC = "Path to indicators file (can be invoked multiple time)"
 HELP_MSG_FAST = "Avoid running time/resource consuming features"
 HELP_MSG_LIST_MODULES = "Print list of available modules and exit"
 HELP_MSG_MODULE = "Name of a single module you would like to run instead of all"
+HELP_MSG_LOAD_MODULE = (
+    "Load custom MVT module(s) from a Python file or folder "
+    "(can be invoked multiple times)"
+)
 HELP_MSG_NONINTERACTIVE = "Don't ask interactive questions during processing"
 HELP_MSG_HASHES = "Generate hashes of all the files analyzed"
 HELP_MSG_VERBOSE = "Verbose mode"
@@ -17,6 +21,7 @@ HELP_MSG_CHECK_IOCS = "Compare stored JSON results to provided indicators"
 HELP_MSG_STIX2 = "Download public STIX2 indicators"
 HELP_MSG_DISABLE_UPDATE_CHECK = "Disable MVT version update check"
 HELP_MSG_DISABLE_INDICATOR_UPDATE_CHECK = "Disable indicators update check"
+HELP_MSG_COMPLETION = "Generate or install shell completion"
 
 # IOS Specific
 HELP_MSG_DECRYPT_BACKUP = "Decrypt an encrypted iTunes backup"

src/mvt/common/module.py

@@ -44,6 +44,7 @@ class MVTModule:
     enabled: bool = True
     slug: Optional[str] = None
     dependencies: Sequence[type["MVTModule"]] = ()
+    supported_commands: Sequence[tuple[str, str]] = ()
 
     def __init__(
         self,

src/mvt/common/module_loader.py

@@ -0,0 +1,127 @@
+# Mobile Verification Toolkit (MVT)
+# Copyright (c) 2021-2026 The MVT Authors.
+# Use of this software is governed by the MVT License 1.1 that can be found at
+#   https://license.mvt.re/1.1/
+
+import hashlib
+import importlib.util
+import inspect
+import os
+import sys
+from pathlib import Path
+from types import ModuleType
+from typing import Iterable, Optional
+
+from .module import MVTModule
+
+MVT_CUSTOM_MODULES_ENV = "MVT_CUSTOM_MODULES"
+
+
+class CustomModuleLoadError(Exception):
+    pass
+
+
+def _module_name_for_path(path: Path) -> str:
+    digest = hashlib.sha256(str(path).encode("utf-8")).hexdigest()[:16]
+    return f"_mvt_custom_module_{path.stem}_{digest}"
+
+
+def _iter_module_files(path: Path) -> Iterable[Path]:
+    if path.is_file():
+        if path.suffix != ".py":
+            raise CustomModuleLoadError(f"Custom module file is not a Python file: {path}")
+        yield path
+        return
+
+    if path.is_dir():
+        for child in sorted(path.iterdir()):
+            if child.name.startswith("."):
+                continue
+            if child.name == "__init__.py":
+                continue
+            if child.is_file() and child.suffix == ".py":
+                yield child
+        return
+
+    raise CustomModuleLoadError(f"Custom module path does not exist: {path}")
+
+
+def _load_python_file(path: Path) -> ModuleType:
+    module_name = _module_name_for_path(path)
+    spec = importlib.util.spec_from_file_location(module_name, path)
+    if spec is None or spec.loader is None:
+        raise CustomModuleLoadError(f"Unable to load custom module file: {path}")
+
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[module_name] = module
+    try:
+        spec.loader.exec_module(module)
+    except Exception as exc:
+        raise CustomModuleLoadError(f"Unable to import custom module {path}: {exc}") from exc
+
+    return module
+
+
+def discover_mvt_modules(module: ModuleType) -> list[type[MVTModule]]:
+    modules = []
+    for _, obj in inspect.getmembers(module, inspect.isclass):
+        if obj is MVTModule:
+            continue
+        if obj.__module__ != module.__name__:
+            continue
+        if not issubclass(obj, MVTModule):
+            continue
+        modules.append(obj)
+
+    return modules
+
+
+def load_custom_modules_from_path(path: str) -> list[type[MVTModule]]:
+    custom_modules: list[type[MVTModule]] = []
+    seen: set[tuple[str, str]] = set()
+    resolved_path = Path(path).expanduser().resolve()
+
+    for module_file in _iter_module_files(resolved_path):
+        loaded_module = _load_python_file(module_file)
+        for module_class in discover_mvt_modules(loaded_module):
+            key = (str(module_file), module_class.__qualname__)
+            if key in seen:
+                continue
+            seen.add(key)
+            custom_modules.append(module_class)
+
+    return custom_modules
+
+
+def load_custom_modules(paths: Optional[Iterable[str]] = None) -> list[type[MVTModule]]:
+    search_paths: list[str] = []
+    env_path = os.environ.get(MVT_CUSTOM_MODULES_ENV)
+    if env_path:
+        search_paths.append(env_path)
+    if paths:
+        search_paths.extend(paths)
+
+    custom_modules: list[type[MVTModule]] = []
+    seen: set[tuple[str, str]] = set()
+    for path in search_paths:
+        for module_class in load_custom_modules_from_path(path):
+            source = Path(inspect.getfile(module_class)).resolve()
+            key = (str(source), module_class.__qualname__)
+            if key in seen:
+                continue
+            seen.add(key)
+            custom_modules.append(module_class)
+
+    return custom_modules
+
+
+def module_supports_command(
+    module_class: type[MVTModule],
+    platform: str,
+    command: str,
+) -> bool:
+    supported_commands = getattr(module_class, "supported_commands", None)
+    if not supported_commands:
+        return True
+
+    return (platform, command) in {tuple(entry) for entry in supported_commands}

src/mvt/ios/cli.py

@@ -11,6 +11,12 @@ import click
 from rich.prompt import Prompt
 
 from mvt.common.cmd_check_iocs import CmdCheckIOCS
+from mvt.common.completion import (
+    SUPPORTED_SHELLS,
+    completion_instructions,
+    generate_completion_script,
+    install_completion_script,
+)
 from mvt.common.logo import logo
 from mvt.common.options import MutuallyExclusiveOption
 from mvt.common.updates import IndicatorsUpdates
@@ -31,6 +37,7 @@ from mvt.common.help import (
     HELP_MSG_OUTPUT,
     HELP_MSG_FAST,
     HELP_MSG_LIST_MODULES,
+    HELP_MSG_LOAD_MODULE,
     HELP_MSG_MODULE,
     HELP_MSG_VERBOSE,
     HELP_MSG_CHECK_FS,
@@ -39,7 +46,9 @@ from mvt.common.help import (
     HELP_MSG_CHECK_IOS_BACKUP,
     HELP_MSG_DISABLE_UPDATE_CHECK,
     HELP_MSG_DISABLE_INDICATOR_UPDATE_CHECK,
+    HELP_MSG_COMPLETION,
 )
+from mvt.common.module_loader import CustomModuleLoadError, load_custom_modules
 from .cmd_check_backup import CmdIOSCheckBackup
 from .cmd_check_fs import CmdIOSCheckFS
 from .decrypt import DecryptBackup
@@ -65,6 +74,13 @@ def _get_disable_flags(ctx):
     )
 
 
+def _load_custom_modules(load_module):
+    try:
+        return load_custom_modules(load_module)
+    except CustomModuleLoadError as exc:
+        raise click.ClickException(str(exc)) from exc
+
+
 # ==============================================================================
 # Main
 # ==============================================================================
@@ -82,6 +98,7 @@ def cli(ctx, disable_update_check, disable_indicator_update_check):
     ctx.ensure_object(dict)
     ctx.obj["disable_version_check"] = disable_update_check
     ctx.obj["disable_indicator_check"] = disable_indicator_update_check
+    if ctx.invoked_subcommand != "completion":
         logo(
             disable_version_check=disable_update_check,
             disable_indicator_check=disable_indicator_update_check,
@@ -96,6 +113,40 @@ def version():
     return
 
 
+# ==============================================================================
+# Command: completion
+# ==============================================================================
+@cli.command("completion", context_settings=CONTEXT_SETTINGS, help=HELP_MSG_COMPLETION)
+@click.argument("shell", required=False, type=click.Choice(SUPPORTED_SHELLS))
+@click.option(
+    "--install",
+    is_flag=True,
+    help="Write completion files and update shell configuration.",
+)
+@click.pass_context
+def completion(ctx, shell, install):
+    program_name = "mvt-ios"
+
+    if shell is None:
+        if install:
+            raise click.UsageError("A shell is required when using --install.")
+        click.echo(completion_instructions(program_name))
+        return
+
+    root_cli = ctx.find_root().command
+
+    if install:
+        script_path = install_completion_script(root_cli, program_name, shell)
+        click.echo(f"Installed {shell} completion to {script_path}")
+        if shell in ("bash", "zsh"):
+            click.echo(f"Updated ~/.{shell}rc")
+        else:
+            click.echo("Fish loads completion files automatically.")
+        return
+
+    click.echo(generate_completion_script(root_cli, program_name, shell))
+
+
 # ==============================================================================
 # Command: decrypt-backup
 # ==============================================================================
@@ -229,15 +280,32 @@ def extract_key(password, key_file, backup_path):
 @click.option("--fast", "-f", is_flag=True, help=HELP_MSG_FAST)
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
 @click.option("--module", "-m", help=HELP_MSG_MODULE)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.option("--hashes", "-H", is_flag=True, help=HELP_MSG_HASHES)
 @click.option("--verbose", "-v", is_flag=True, help=HELP_MSG_VERBOSE)
 @click.argument("BACKUP_PATH", type=click.Path(exists=True))
 @click.pass_context
 def check_backup(
-    ctx, iocs, output, fast, list_modules, module, hashes, verbose, backup_path
+    ctx,
+    iocs,
+    output,
+    fast,
+    list_modules,
+    module,
+    load_module,
+    hashes,
+    verbose,
+    backup_path,
 ):
     set_verbose_logging(verbose)
     module_options = {"fast_mode": fast}
+    custom_modules = _load_custom_modules(load_module)
 
     cmd = CmdIOSCheckBackup(
         target_path=backup_path,
@@ -248,6 +316,7 @@ def check_backup(
         hashes=hashes,
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
     )
 
     if list_modules:
@@ -277,13 +346,32 @@ def check_backup(
 @click.option("--fast", "-f", is_flag=True, help=HELP_MSG_FAST)
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
 @click.option("--module", "-m", help=HELP_MSG_MODULE)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.option("--hashes", "-H", is_flag=True, help=HELP_MSG_HASHES)
 @click.option("--verbose", "-v", is_flag=True, help=HELP_MSG_VERBOSE)
 @click.argument("DUMP_PATH", type=click.Path(exists=True))
 @click.pass_context
-def check_fs(ctx, iocs, output, fast, list_modules, module, hashes, verbose, dump_path):
+def check_fs(
+    ctx,
+    iocs,
+    output,
+    fast,
+    list_modules,
+    module,
+    load_module,
+    hashes,
+    verbose,
+    dump_path,
+):
     set_verbose_logging(verbose)
     module_options = {"fast_mode": fast}
+    custom_modules = _load_custom_modules(load_module)
 
     cmd = CmdIOSCheckFS(
         target_path=dump_path,
@@ -294,6 +382,7 @@ def check_fs(ctx, iocs, output, fast, list_modules, module, hashes, verbose, dum
         hashes=hashes,
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
     )
 
     if list_modules:
@@ -321,15 +410,25 @@ def check_fs(ctx, iocs, output, fast, list_modules, module, hashes, verbose, dum
 )
 @click.option("--list-modules", "-l", is_flag=True, help=HELP_MSG_LIST_MODULES)
 @click.option("--module", "-m", help=HELP_MSG_MODULE)
+@click.option(
+    "--load-module",
+    type=click.Path(exists=True),
+    multiple=True,
+    default=[],
+    help=HELP_MSG_LOAD_MODULE,
+)
 @click.argument("FOLDER", type=click.Path(exists=True))
 @click.pass_context
-def check_iocs(ctx, iocs, list_modules, module, folder):
+def check_iocs(ctx, iocs, list_modules, module, load_module, folder):
+    custom_modules = _load_custom_modules(load_module)
     cmd = CmdCheckIOCS(
         target_path=folder,
         ioc_files=iocs,
         module_name=module,
         disable_version_check=_get_disable_flags(ctx)[0],
         disable_indicator_check=_get_disable_flags(ctx)[1],
+        custom_modules=custom_modules,
+        platform="ios",
     )
     cmd.modules = BACKUP_MODULES + FS_MODULES + MIXED_MODULES
 

src/mvt/ios/cmd_check_backup.py

@@ -8,6 +8,7 @@ from typing import Optional
 
 from mvt.common.command import Command
 from mvt.common.indicators import Indicators
+from mvt.common.module import MVTModule
 
 from .modules.backup import BACKUP_MODULES
 from .modules.mixed import MIXED_MODULES
@@ -29,6 +30,7 @@ class CmdIOSCheckBackup(Command):
         sub_command: bool = False,
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
     ) -> None:
         super().__init__(
             target_path=target_path,
@@ -43,8 +45,10 @@ class CmdIOSCheckBackup(Command):
             log=log,
             disable_version_check=disable_version_check,
             disable_indicator_check=disable_indicator_check,
+            custom_modules=custom_modules,
         )
 
+        self.platform = "ios"
         self.name = "check-backup"
         self.modules = BACKUP_MODULES + MIXED_MODULES
 

src/mvt/ios/cmd_check_fs.py

@@ -8,6 +8,7 @@ from typing import Optional
 
 from mvt.common.command import Command
 from mvt.common.indicators import Indicators
+from mvt.common.module import MVTModule
 
 from .modules.fs import FS_MODULES
 from .modules.mixed import MIXED_MODULES
@@ -29,6 +30,7 @@ class CmdIOSCheckFS(Command):
         sub_command: bool = False,
         disable_version_check: bool = False,
         disable_indicator_check: bool = False,
+        custom_modules: Optional[list[type[MVTModule]]] = None,
     ) -> None:
         super().__init__(
             target_path=target_path,
@@ -42,8 +44,10 @@ class CmdIOSCheckFS(Command):
             log=log,
             disable_version_check=disable_version_check,
             disable_indicator_check=disable_indicator_check,
+            custom_modules=custom_modules,
         )
 
+        self.platform = "ios"
         self.name = "check-fs"
         self.modules = FS_MODULES + MIXED_MODULES
 

tests/common/test_command.py

@@ -42,6 +42,19 @@ class IndependentModule(RecordingModule):
     pass
 
 
+class CustomIOSBackupModule(RecordingModule):
+    supported_commands = (("ios", "check-backup"),)
+
+
+class CustomIOSFSModule(RecordingModule):
+    supported_commands = (("ios", "check-fs"),)
+
+
+class CustomDependsOnBuiltin(RecordingModule):
+    supported_commands = (("ios", "check-backup"),)
+    dependencies = (FirstModule,)
+
+
 class RecordingCommand(Command):
     def init(self):
         self.initialized = True
@@ -132,3 +145,46 @@ class TestCommand:
         assert RecordingModule.run_order == []
         assert not hasattr(cmd, "initialized")
         assert "depends on unavailable module UnavailableModule" in caplog.text
+
+    def test_custom_modules_are_filtered_before_ordering(self):
+        cmd = RecordingCommand()
+        cmd.platform = "ios"
+        cmd.name = "check-backup"
+        cmd.modules = [FirstModule]
+        cmd.custom_modules = [CustomIOSBackupModule, CustomIOSFSModule]
+
+        assert [module.__name__ for module in cmd._ordered_modules()] == [
+            "FirstModule",
+            "CustomIOSBackupModule",
+        ]
+
+    def test_selected_custom_module_runs(self):
+        cmd = RecordingCommand(module_name="CustomIOSBackupModule")
+        cmd.platform = "ios"
+        cmd.name = "check-backup"
+        cmd.custom_modules = [CustomIOSBackupModule]
+
+        cmd.run()
+
+        assert RecordingModule.run_order == ["CustomIOSBackupModule"]
+
+    def test_selected_unsupported_custom_module_does_not_run(self):
+        cmd = RecordingCommand(module_name="CustomIOSFSModule")
+        cmd.platform = "ios"
+        cmd.name = "check-backup"
+        cmd.custom_modules = [CustomIOSFSModule]
+
+        cmd.run()
+
+        assert RecordingModule.run_order == []
+
+    def test_custom_module_dependencies_use_topological_order(self):
+        cmd = RecordingCommand(module_name="CustomDependsOnBuiltin")
+        cmd.platform = "ios"
+        cmd.name = "check-backup"
+        cmd.modules = [SecondModule, FirstModule]
+        cmd.custom_modules = [CustomDependsOnBuiltin]
+
+        cmd.run()
+
+        assert RecordingModule.run_order == ["FirstModule", "CustomDependsOnBuiltin"]

tests/common/test_module_loader.py

@@ -0,0 +1,145 @@
+import pytest
+
+from mvt.common.module import MVTModule
+from mvt.common.module_loader import (
+    CustomModuleLoadError,
+    load_custom_modules,
+    load_custom_modules_from_path,
+    module_supports_command,
+)
+
+
+MODULE_TEMPLATE = """
+from mvt.common.module import MVTModule
+
+
+class {name}(MVTModule):
+    supported_commands = {supported_commands!r}
+
+    def run(self):
+        pass
+
+    def check_indicators(self):
+        pass
+
+    def serialize(self, result):
+        return None
+"""
+
+
+def _write_module(path, name, supported_commands=()):
+    path.write_text(
+        MODULE_TEMPLATE.format(
+            name=name,
+            supported_commands=supported_commands,
+        ),
+        encoding="utf-8",
+    )
+    return path
+
+
+def test_load_custom_modules_from_python_file(tmp_path):
+    module_path = _write_module(tmp_path / "custom.py", "FileModule")
+
+    modules = load_custom_modules_from_path(str(module_path))
+
+    assert [module.__name__ for module in modules] == ["FileModule"]
+    assert issubclass(modules[0], MVTModule)
+
+
+def test_load_custom_modules_from_folder_in_sorted_order(tmp_path):
+    _write_module(tmp_path / "b_module.py", "BModule")
+    _write_module(tmp_path / "a_module.py", "AModule")
+    _write_module(tmp_path / ".hidden.py", "HiddenModule")
+    _write_module(tmp_path / "__init__.py", "InitModule")
+    nested = tmp_path / "nested"
+    nested.mkdir()
+    _write_module(nested / "nested_module.py", "NestedModule")
+
+    modules = load_custom_modules_from_path(str(tmp_path))
+
+    assert [module.__name__ for module in modules] == ["AModule", "BModule"]
+
+
+def test_discovery_ignores_imported_base_and_unrelated_classes(tmp_path):
+    module_path = tmp_path / "custom.py"
+    module_path.write_text(
+        """
+from mvt.common.module import MVTModule
+
+
+class Unrelated:
+    pass
+
+
+class DiscoveredModule(MVTModule):
+    def run(self):
+        pass
+
+    def check_indicators(self):
+        pass
+
+    def serialize(self, result):
+        return None
+""",
+        encoding="utf-8",
+    )
+
+    modules = load_custom_modules_from_path(str(module_path))
+
+    assert [module.__name__ for module in modules] == ["DiscoveredModule"]
+
+
+def test_load_custom_modules_deduplicates_same_class(tmp_path):
+    module_path = _write_module(tmp_path / "custom.py", "DuplicateModule")
+
+    modules = load_custom_modules([str(module_path), str(module_path)])
+
+    assert [module.__name__ for module in modules] == ["DuplicateModule"]
+
+
+def test_load_custom_modules_raises_for_missing_path(tmp_path):
+    with pytest.raises(CustomModuleLoadError, match="does not exist"):
+        load_custom_modules_from_path(str(tmp_path / "missing.py"))
+
+
+def test_load_custom_modules_raises_for_import_error(tmp_path):
+    module_path = tmp_path / "broken.py"
+    module_path.write_text("raise RuntimeError('broken import')", encoding="utf-8")
+
+    with pytest.raises(CustomModuleLoadError, match="broken import"):
+        load_custom_modules_from_path(str(module_path))
+
+
+def test_load_custom_modules_loads_env_folder_first(tmp_path, monkeypatch):
+    env_folder = tmp_path / "env"
+    env_folder.mkdir()
+    cli_folder = tmp_path / "cli"
+    cli_folder.mkdir()
+    _write_module(env_folder / "env_module.py", "EnvModule")
+    _write_module(cli_folder / "cli_module.py", "CliModule")
+    monkeypatch.setenv("MVT_CUSTOM_MODULES", str(env_folder))
+
+    modules = load_custom_modules([str(cli_folder)])
+
+    assert [module.__name__ for module in modules] == ["EnvModule", "CliModule"]
+
+
+def test_module_supports_command_defaults_to_all_commands(tmp_path):
+    module_path = _write_module(tmp_path / "custom.py", "DefaultModule")
+    module = load_custom_modules_from_path(str(module_path))[0]
+
+    assert module_supports_command(module, "ios", "check-backup")
+    assert module_supports_command(module, "android", "check-bugreport")
+
+
+def test_module_supports_command_honors_supported_commands(tmp_path):
+    module_path = _write_module(
+        tmp_path / "custom.py",
+        "SpecificModule",
+        (("ios", "check-backup"),),
+    )
+    module = load_custom_modules_from_path(str(module_path))[0]
+
+    assert module_supports_command(module, "ios", "check-backup")
+    assert not module_supports_command(module, "ios", "check-fs")

tests/test_completion.py

@@ -0,0 +1,78 @@
+# Mobile Verification Toolkit (MVT)
+# Copyright (c) 2021-2023 The MVT Authors.
+# Use of this software is governed by the MVT License 1.1 that can be found at
+#   https://license.mvt.re/1.1/
+
+from click.testing import CliRunner
+
+from mvt.android.cli import cli as android_cli
+from mvt.ios.cli import cli as ios_cli
+
+
+class TestCompletionCommand:
+    def test_completion_prints_instructions_by_default(self):
+        runner = CliRunner()
+        result = runner.invoke(ios_cli, ["completion"])
+
+        assert result.exit_code == 0
+        assert "Shell completion for mvt-ios" in result.output
+        assert "mvt-ios completion bash > ~/.mvt-ios-complete.bash" in result.output
+        assert "Mobile Verification Toolkit" not in result.output
+
+    def test_completion_prints_bash_script(self):
+        runner = CliRunner()
+        result = runner.invoke(ios_cli, ["completion", "bash"])
+
+        assert result.exit_code == 0
+        assert "_MVT_IOS_COMPLETE=bash_complete" in result.output
+        assert "complete -o nosort" in result.output
+        assert "mvt-ios" in result.output
+        assert "Mobile Verification Toolkit" not in result.output
+
+    def test_completion_prints_fish_script(self):
+        runner = CliRunner()
+        result = runner.invoke(android_cli, ["completion", "fish"])
+
+        assert result.exit_code == 0
+        assert "_MVT_ANDROID_COMPLETE=fish_complete" in result.output
+        assert "complete --no-files --command mvt-android" in result.output
+        assert "Mobile Verification Toolkit" not in result.output
+
+    def test_completion_install_updates_bashrc_once(self, tmp_path, monkeypatch):
+        monkeypatch.setenv("HOME", str(tmp_path))
+        runner = CliRunner()
+
+        result = runner.invoke(ios_cli, ["completion", "bash", "--install"])
+        assert result.exit_code == 0
+
+        script_path = tmp_path / ".mvt-ios-complete.bash"
+        bashrc_path = tmp_path / ".bashrc"
+        assert script_path.exists()
+        assert "_MVT_IOS_COMPLETE=bash_complete" in script_path.read_text(
+            encoding="utf-8"
+        )
+        bashrc = bashrc_path.read_text(encoding="utf-8")
+        assert "[ -f" in bashrc
+        assert ".mvt-ios-complete.bash" in bashrc
+
+        result = runner.invoke(ios_cli, ["completion", "bash", "--install"])
+        assert result.exit_code == 0
+        assert bashrc_path.read_text(encoding="utf-8") == bashrc
+
+    def test_completion_install_fish_does_not_update_shell_rc(
+        self, tmp_path, monkeypatch
+    ):
+        monkeypatch.setenv("HOME", str(tmp_path))
+        runner = CliRunner()
+
+        result = runner.invoke(android_cli, ["completion", "fish", "--install"])
+
+        assert result.exit_code == 0
+        script_path = (
+            tmp_path / ".config" / "fish" / "completions" / "mvt-android.fish"
+        )
+        assert script_path.exists()
+        assert "_MVT_ANDROID_COMPLETE=fish_complete" in script_path.read_text(
+            encoding="utf-8"
+        )
+        assert not (tmp_path / ".fishrc").exists()

tests/test_custom_modules.py

@@ -0,0 +1,193 @@
+from click.testing import CliRunner
+
+from mvt.android.cli import check_bugreport
+from mvt.android.cmd_check_androidqf import CmdAndroidCheckAndroidQF
+from mvt.android.cmd_check_backup import CmdAndroidCheckBackup
+from mvt.android.cmd_check_bugreport import CmdAndroidCheckBugreport
+from mvt.android.cmd_check_intrusion_logs import CmdAndroidCheckIntrusionLogs
+from mvt.common.module import MVTModule
+from mvt.ios.cli import check_backup, check_fs
+
+
+CUSTOM_MODULE = """
+from mvt.common.module import MVTModule
+
+
+class {name}(MVTModule):
+    supported_commands = {supported_commands!r}
+    slug = "{slug}"
+
+    def run(self):
+        self.results = [{{"message": "custom module ran"}}]
+
+    def check_indicators(self):
+        pass
+
+    def serialize(self, result):
+        return None
+"""
+
+
+def _write_custom_module(path, name, supported_commands, slug=None):
+    path.write_text(
+        CUSTOM_MODULE.format(
+            name=name,
+            supported_commands=supported_commands,
+            slug=slug or name.lower(),
+        ),
+        encoding="utf-8",
+    )
+    return path
+
+
+def test_load_module_appears_only_for_supported_cli_command(tmp_path):
+    module_path = _write_custom_module(
+        tmp_path / "custom.py",
+        "IOSBackupOnlyModule",
+        (("ios", "check-backup"),),
+    )
+
+    backup_result = CliRunner().invoke(
+        check_backup,
+        ["--list-modules", "--load-module", str(module_path), str(tmp_path)],
+    )
+    fs_result = CliRunner().invoke(
+        check_fs,
+        ["--list-modules", "--load-module", str(module_path), str(tmp_path)],
+    )
+
+    assert backup_result.exit_code == 0
+    assert "IOSBackupOnlyModule" in backup_result.output
+    assert fs_result.exit_code == 0
+    assert "IOSBackupOnlyModule" not in fs_result.output
+
+
+def test_module_option_runs_supported_custom_module(tmp_path):
+    module_path = _write_custom_module(
+        tmp_path / "custom.py",
+        "CustomRunModule",
+        (("ios", "check-backup"),),
+        slug="custom_run_module",
+    )
+    output_path = tmp_path / "out"
+
+    result = CliRunner().invoke(
+        check_backup,
+        [
+            "--module",
+            "CustomRunModule",
+            "--load-module",
+            str(module_path),
+            "--output",
+            str(output_path),
+            str(tmp_path),
+        ],
+    )
+
+    assert result.exit_code == 0
+    assert (output_path / "custom_run_module.json").exists()
+
+
+def test_custom_modules_load_from_environment_without_cli_flag(tmp_path, monkeypatch):
+    custom_modules_path = tmp_path / "custom_modules"
+    custom_modules_path.mkdir()
+    _write_custom_module(
+        custom_modules_path / "env_module.py",
+        "EnvBugreportModule",
+        (("android", "check-bugreport"),),
+    )
+    monkeypatch.setenv("MVT_CUSTOM_MODULES", str(custom_modules_path))
+
+    result = CliRunner().invoke(check_bugreport, ["--list-modules", str(tmp_path)])
+
+    assert result.exit_code == 0
+    assert "EnvBugreportModule" in result.output
+
+
+class NestedBugreportModule(MVTModule):
+    supported_commands = (("android", "check-bugreport"),)
+
+
+class NestedBackupModule(MVTModule):
+    supported_commands = (("android", "check-backup"),)
+
+
+class NestedIntrusionLogsModule(MVTModule):
+    supported_commands = (("android", "check-intrusion-logs"),)
+
+
+class NestedAndroidQFModule(MVTModule):
+    supported_commands = (("android", "check-androidqf"),)
+
+
+class DummyZip:
+    def close(self):
+        pass
+
+
+def test_androidqf_propagates_custom_modules_to_nested_commands(tmp_path, monkeypatch):
+    records = {}
+    custom_modules = [
+        NestedBugreportModule,
+        NestedBackupModule,
+        NestedIntrusionLogsModule,
+        NestedAndroidQFModule,
+    ]
+    cmd = CmdAndroidCheckAndroidQF(
+        target_path=str(tmp_path),
+        custom_modules=custom_modules,
+    )
+
+    def record_available(name):
+        def _record(command):
+            records[name] = [
+                module.__name__
+                for module in command._available_modules()
+                if module.__name__.startswith("Nested")
+            ]
+
+        return _record
+
+    monkeypatch.setattr(cmd, "load_bugreport", lambda: DummyZip())
+    monkeypatch.setattr(
+        CmdAndroidCheckBugreport,
+        "from_zip",
+        lambda self, bugreport: None,
+    )
+    monkeypatch.setattr(
+        CmdAndroidCheckBugreport,
+        "run",
+        record_available("bugreport"),
+    )
+
+    monkeypatch.setattr(cmd, "load_backup", lambda: b"")
+    monkeypatch.setattr(CmdAndroidCheckBackup, "from_ab", lambda self, backup: None)
+    monkeypatch.setattr(
+        CmdAndroidCheckBackup,
+        "run",
+        record_available("backup"),
+    )
+
+    intrusion_logs_path = tmp_path / "intrusion_logs"
+    intrusion_logs_path.mkdir()
+    setattr(cmd, "_CmdAndroidCheckAndroidQF__format", "dir")
+    setattr(
+        cmd,
+        "_CmdAndroidCheckAndroidQF__files",
+        ["androidqf/intrusion_logs/security.txt"],
+    )
+    monkeypatch.setattr(cmd, "_read_device_timezone", lambda: None)
+    monkeypatch.setattr(
+        CmdAndroidCheckIntrusionLogs,
+        "run",
+        record_available("intrusion_logs"),
+    )
+
+    assert cmd.run_bugreport_cmd()
+    assert cmd.run_backup_cmd()
+    assert cmd.run_intrusion_logs_cmd()
+    assert records == {
+        "bugreport": ["NestedBugreportModule"],
+        "backup": ["NestedBackupModule"],
+        "intrusion_logs": ["NestedIntrusionLogsModule"],
+    }