How to Detect PlankFilza File System Tool, Protect iOS Apps

Last updated December 6, 2023 by Appdome

Learn to Detect PlankFilza in iOS apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What is PlankFilza?

PlankFilza is an iOS utility or ‘tweak’ that allows access to the iOS file system/manager. Even though PlankFilza does not require the phone to be jailbroken, it is most often used in combination with Jailbreaking. This combination is used because the elevated level of privileges Jailbreaking provides enables the attacker to compromise the target app much more easily.

PlankFilza works by taking advantage of an exploit in iOS, in order to get limited read/write permissions to the iOS file system of non-jailbroken iOS devices. Once PlankFilza is installed, you can read files from any directory and write to the /var and/tmp locations.

Why Detect PlankFilza in iOS Apps?

While PlankFilza does not provide the wide range of exploits that full-fledged jailbreak techniques provide, it is still an extremely dangerous and potent challenge for security professionals. The fact that PlankFilza is often used in combination with jailbreaking is another significant reason for blocking this utility, and therefore Appdome blocks PlankFilza as part of the protection provided by enabling the Detect Jailbreak feature.

Prerequisites for Using Jailbreak Detection:

To use Appdome’s mobile app security build system to Detect PlankFilza , you’ll need:

Detect PlankFilza on iOS apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending iOS Apps that Detect PlankFilza without an SDK or gateway:

  1. Upload the Mobile App to Appdome.

    1. Upload an app to Appdome’s Mobile App Security Build System

    2. Upload Method: Appdome Console or DEV-API
    3. iOS Formats: .ipa
    4. Jailbreak Detection Compatible With: Obj-C, Java, Swift, Flutter, React Native, Unity, Xamarin, Cordova and more
  2. Build the feature: Jailbreak Detection.

    1. Building Jailbreak Detection by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Jailbreak Detection feature as shown below:
      2. fusion set that contains Jailbreak Detection

        Figure 1: Fusion Set that will contain the Jailbreak Detection feature
        Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required).

      3. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Jailbreak Detection feature via Appdome Console, to add the Jailbreak Detection feature to this Fusion Set.

      4. Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set, as shown in Figure 1 above, and get the Fusion Set ID from the Fusion Set Detail Summary (as shown below): fusion Set Detail Summary image

        Figure 2: Fusion Set Detail Summary
        Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory).

      5. Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, App Center, Jenkins, Travis, Team City, Circle CI or other system:
        1. Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
        2. Look for sample APIs in Appdome’s GitHub Repository
    2. Building the Jailbreak Detection feature via Appdome Console

      To build the Jailbreak Detection protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Security Tab > OS Integrity section.
      2. When you select the Jailbreak Detection you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Jailbreak Detection

        Fusion Set applied Jailbreak Detection

        Figure 4: Fusion Set that displays the newly added Jailbreak Detection protection

      3. Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for Jailbreak Detection:
        1. Threat-Events™ OFF > In-App Defense

          If the Threat-Events™ setting is cleared (not selected). Appdome will detect and defend the user and app by enforcing Detect PlankFilza.

        2. Threat-Events™ ON > In-App Detection

          When this setting is used, Appdome detects that iOS has been compromised via jailbreaking and passes Appdome’s Threat-Event™ attack intelligence to the app’s business logic for processing, enforcement, and user notification. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for Jailbreak Detection Intelligence and Control in Mobile Apps.

        3. Threat-Events™ ON > In-App Defense

          When this setting is used, Appdome detects and defends against PlankFilza (same as Appdome Enforce) and passes Appdome’s Threat-Event™ attack intelligence the app’s business logic for processing. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for Jailbreak Detection Intelligence and Control in Mobile Apps.

      4. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
    Congratulations!  The Jailbreak Detection protection is now added to the mobile app

Using Threat-Events™ for PlankFilza Intelligence and Control in iOS Apps

Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when PlankFilza is detected. To consume and use Threat-Events™ for PlankFilza in iOS Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for PlankFilza shown below.

The specifications and options for Threat-Events™ for PlankFilza are:

Threat-Event™ Elements Detect PlankFilza Method Detail
Appdome Feature Name Jailbreak Detection
Threat-Event Mode
OFF, IN-APP DEFENSE Appdome detects, defends and notifies user (standard OS dialog) using customizable messaging.
ON, IN-APP DETECTION Appdome detects the attack or threat and passes the event in a standard format to the app for processing (app chooses how and when to enforce).
ON, IN-APP DEFENSE Uses Appdome Enforce mode for any attack or threat and passes the event in a standard format to the app for processing (gather intel on attacks and threats without losing any protection).
Certified Secure™ Threat Event Check
Visible in ThreatScope™
Developer Parameters for Detecting PlankFilza Threat-Event™
Threat-Event NAME JailbrokenDevice
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF 6901
Threat-Event SCORE
currentThreatEventScore Current Threat-Event score
threatEventsScore Total Threat-events score
Threat-Event Context Keys
message Message displayed for the user on event
externalID The external ID of the event which can be listened via Threat Events
osVersion OS version of the current device
deviceModel Current device model
deviceManufacturer The manufacturer of the current device
fusedAppToken The task ID of the Appdome fusion of the currently running app
kernelInfo Info about the kernel: system name, node name, release, version and machine.
carrierPlmn PLMN of the device
deviceID Current device ID
reasonCode Reason code of the occured event
buildDate Appdome fusion date of the current application
devicePlatform OS name of the current device
carrierName Carrier name of the current device
updatedOSVersion Is the OS version up to date
timeZone Time zone
deviceFaceDown Is the device face down
locationLong Location longitude conditioned by location permission
locationLat Location latitude conditioned by location permission
locationState Location state conditioned by location permission
wifiSsid Wifi SSID
wifiSsidPermissionStatus Wifi SSID permission status
internalError Internal error code as hex
extendedMessageText Internal error code
rInternalErrorCode Internal error code
reason Reason for the root detection

With Threat-Events™ enabled (turned ON), iOS developers can get detailed attack intelligence and granular defense control in iOS applications and create amazing user experiences for all mobile end users when PlankFilza is detected.

The following is a code sample for native iOS apps, which uses all values in the specification above for Jailbreak Detection:


Using Appdome, there are no development or coding prerequisites to build secured iOS Apps by using Jailbreak Detection. There is no SDK and no library to code or implement in the app and no gateway to deploy in your network. All protections are built into each app and the resulting app is self-defending and self-protecting.

Releasing and Publishing Mobile Apps with Jailbreak Detection

After successfully securing your app by using Appdome, there are several available options to complete your project, depending on your app lifecycle or workflow. These include:

Related Articles:

If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.

Thank you!

Thanks for visiting Appdome! Our mission is to secure every app on the planet by making mobile app security easy. We hope we’re living up to the mission with your project.

Want a Demo?

Jailbreak & Root Detection

TomWe're here to help
We'll get back to you in 24 hours to schedule your demo.