Android 17 Advanced Protection Locks Accessibility Services to Verified Accessibility Tools

Google has announced a new security measure that limits access to Android’s accessibility services to verified applications classified as Accessibility Tools when Advanced Protection is enabled.

With malicious Android applications abusing the API serving as the main conduit for malware and financial fraud, the tech giant said the move would block a major attack pathway. Advanced Protection is a security setting that turns on all Android’s security features to secure the device against potential threats.

“In Android 17, enabling Advanced Protection automatically restricts AccessibilityService access exclusively to verified applications categorized as Accessibility Tools, closing off a major avenue of attack while preserving vital assistive technology,” Google said Thursday.

The Android AccessibilityService API is a powerful framework that allows an application to run in the background, intercept user interface events, and interact with other applications on the user’s behalf.

Although its primary purpose is to assist users with disabilities, such as through screen readers or voice control systems, its privileged access has been abused by banking trojans and spyware to extract sensitive data and perform malicious actions without needing root access.

Put differently, once a user is tricked into enabling the service under a social engineering pretext, the malware can turn genuine assistive features into potent cyber weapons to programmatically initiate fraudulent fund transfers from installed financial apps, log keystrokes, draw fake login screens over legitimate apps, and grant itself additional sensitive permissions.

“Because accessibility services are designed to interact directly with the screen, malicious actors can exploit them to read sensitive data, install malware, or block uninstallation,” Google said.

In recent years, Google has taken a number of steps to counter this abuse –

• Blocking sideloaded apps from enabling accessibility services
• In-call protections that prevent users from disabling Google Play Protect, sideloading apps, or granting accessibility permissions
• Setting the accessibilityDataSensitive flag to let app developers mark a view or composable as containing sensitive data to block potentially malicious apps from accessing sensitive view data or performing interactions on it
• Using Android Advanced Protection Mode (AAPM) to prevent certain kinds of apps from using the accessibility services API

Alongside Accessibility protection, Android 17 also brings a number of other security improvements –

• Intrusion Logging, which enables persistent, privacy-preserving forensics logging to investigate sophisticated spyware attacks
• USB Protection, which prevents attackers from gaining unauthorized access to your device through a physical USB connection
• Disable WebGPU, which reduces exposure to sophisticated browser-based exploits
• Failed Authentication Lock, which protects against physical tampering and brute-force attempts by completely locking down the device to prevent further probing
• View Supporting Apps, which allows users to view which installed apps have checked the Advanced Protection status

“Developers can be notified when Advanced Protection is enabled so that they can auto-enable any features they have for this user population,” Google said. “If you already use Advanced Protection, you will see a notification once these new capabilities arrive on your device. To take advantage of the new forensic capabilities, navigate to your Advanced Protection settings page and manually enable Intrusion Logging.”