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Input Prompt

The operating system and installed applications often have legitimate needs to prompt the user for sensitive information such as account credentials, bank account information, or Personally Identifiable Information (PII). Adversaries may mimic this functionality to prompt users for sensitive information.

Compared to traditional PCs, the constrained display size of mobile devices may impair the ability to provide users with contextual information, making users more susceptible to this technique’s use.[1]

Specific approaches to this technique include:

Impersonate the identity of a legitimate application

A malicious application could impersonate the identity of a legitimate application (e.g. use the same application name and/or icon) and get installed on the device. The malicious app could then prompt the user for sensitive information.[2]

Display a prompt on top of a running legitimate application

A malicious application could display a prompt on top of a running legitimate application to trick users into entering sensitive information into the malicious application rather than the legitimate application. Typically, the malicious application would need to know when the targeted application (and individual activity within the targeted application) is running in the foreground, so that the malicious application knows when to display its prompt. Android 5.0 and 5.1.1, respectively, increased the difficulty of determining the current foreground application through modifications to the ActivityManager API.[3][4]. A malicious application can still abuse Android’s accessibility features to determine which application is currently in the foreground.[5] Approaches to display a prompt include:

  • A malicious application could start a new activity on top of a running legitimate application.[1][6] Android 10 places new restrictions on the ability for an application to start a new activity on top of another application, which may make it more difficult for adversaries to utilize this technique.[7]
  • A malicious application could create an application overlay window on top of a running legitimate application. Applications must hold the SYSTEM_ALERT_WINDOW permission to create overlay windows. This permission is handled differently than typical Android permissions, and at least under certain conditions is automatically granted to applications installed from the Google Play Store.[8][9][10] The SYSTEM_ALERT_WINDOW permission and its associated ability to create application overlay windows are expected to be deprecated in a future release of Android in favor of a new API.[11]

Fake device notifications

A malicious application could send fake device notifications to the user. Clicking on the device notification could trigger the malicious application to display an input prompt.[12]

ID: T1411
Sub-techniques:  No sub-techniques
Tactic Type: Post-Adversary Device Access
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Tactic: Credential Access
ⓘ
Platforms: Android, iOS
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MTC ID: APP-31
Version: 2.1
Created: 25 October 2017
Last Modified: 24 June 2020

Procedure Examples

ID Name Description
S0422 Anubis

Anubis can create overlays to capture user credentials for targeted applications.[13]
S0480 Cerberus

Cerberus can generate fake notifications and launch overlay attacks against attacker-specified applications.[14]
S0301 Dendroid

Dendroid can open a dialog box to ask the user for passwords.[15]
S0478 EventBot

EventBot can display popups over running applications.[16]
S0522 Exobot

Exobot can show phishing popups when a targeted application is running.[17]
S0423 Ginp

Ginp can use a multi-step phishing overlay to capture banking credentials and then credit card numbers after login.[18]
S0536 GPlayed

GPlayed can show a phishing WebView pretending to be a Google service that collects credit card information.[19]
S0406 Gustuff

Gustuff uses WebView overlays to prompt the user for their device unlock code, as well as banking and cryptocurrency application credentials. Gustuff can also send push notifications pretending to be from a bank, triggering a phishing overlay. [20][12]
S0485 Mandrake

Mandrake can manipulate visual components to trick the user into granting dangerous permissions, and can use phishing overlays and JavaScript injection to capture credentials.[21]
S0317 Marcher

Marcher attempts to overlay itself on top of legitimate banking apps in an effort to capture user credentials. Marcher also attempts to overlay itself on top of legitimate apps such as the Google Play Store in an effort to capture user credit card information.[22]
S0399 Pallas

Pallas uses phishing popups to harvest user credentials.[23]
S0539 Red Alert 2.0

Red Alert 2.0 has used malicious overlays to collect banking credentials.[24]
S0403 Riltok

Riltok can open a fake Google Play screen requesting bank card credentials and mimic the screen of relevant mobile banking apps to request user/bank card details.[25]
S0411 Rotexy

Rotexy can use phishing overlays to capture users' credit card information.[26]
S0545 TERRACOTTA

TERRACOTTA has displayed a form to collect user data after installation.[27]
S0558 Tiktok Pro

Tiktok Pro can launch a fake Facebook login page.[28]
S0298 Xbot

Xbot uses phishing pages mimicking Google Play's payment interface as well as bank login pages.[29]
S0297 XcodeGhost

XcodeGhost can prompt a fake alert dialog to phish user credentials.[30]

Mitigations

ID Mitigation Description
M1005 Application Vetting
M1012 Enterprise Policy

An EMM/MDM can use the Android DevicePolicyManager.setPermittedAccessibilityServices method to set an explicit list of applications that are allowed to use Android's accessibility features.
M1006 Use Recent OS Version

Detection

The user can view and manage which applications hold the SYSTEM_ALERT_WINDOW permission to create overlay windows on top of other apps through the device settings in Apps & notifications -> Special app access -> Display over other apps (the exact menu location may vary between Android versions).

References

  1. A.P. Felt and D. Wagner. (2011, May 26). Phishing on Mobile Devices. Retrieved August 25, 2016.
  2. Lukáš Štefanko. (2016, July 7). Fake finance apps on Google Play target users from around the world. Retrieved September 24, 2018.
  3. Android. (n.d.). ActivityManager getRunningTasks documentation. Retrieved January 19, 2017.
  4. Various. (n.d.). Android 5.1.1 and above - getRunningAppProcesses() returns my application package only. Retrieved January 19, 2017.
  5. ThreatFabric. (2019, August). Cerberus - A new banking Trojan from the underworld. Retrieved September 18, 2019.
  6. R. Hassell. (2011, October 12-13). Exploiting Androids for Fun and Profit. Retrieved October 10, 2019.
  7. Android Developers. (n.d.). Restrictions on starting activities from the background. Retrieved September 18, 2019.
  8. Fratantonio, Y., et al.. (2017). Cloak & Dagger. Retrieved September 18, 2019.
  9. Ramirez, T.. (2017, May 25). ‘SAW’-ing through the UI: Android overlay malware and the System Alert Window permission explained. Retrieved September 18, 2019.
  10. Yair Amit. (2016, March 3). “Accessibility Clickjacking” – The Next Evolution in Android Malware that Impacts More Than 500 Million Devices. Retrieved December 21, 2016.
  11. Rahman, M.. (2019, May 8). Bubbles in Android Q will fully replace the overlay API in a future Android version. Retrieved September 18, 2019.
  12. Group-IB. (2019, March 28). Group-IB uncovers Android Trojan named «Gustuff» capable of targeting more than 100 global banking apps, cryptocurrency and marketplace applications. Retrieved September 3, 2019.
  13. M. Feller. (2020, February 5). Infostealer, Keylogger, and Ransomware in One: Anubis Targets More than 250 Android Applications. Retrieved April 8, 2020.
  14. Threat Fabric. (2019, August). Cerberus - A new banking Trojan from the underworld. Retrieved June 26, 2020.
  15. Marc Rogers. (2014, March 6). Dendroid malware can take over your camera, record audio, and sneak into Google Play. Retrieved December 22, 2016.
  1. D. Frank, L. Rochberger, Y. Rimmer, A. Dahan. (2020, April 30). EventBot: A New Mobile Banking Trojan is Born. Retrieved June 26, 2020.
  2. Threat Fabric. (2017, February). Exobot - Android banking Trojan on the rise. Retrieved October 29, 2020.
  3. ThreatFabric. (2019, November). Ginp - A malware patchwork borrowing from Anubis. Retrieved April 8, 2020.
  4. V. Ventura. (2018, October 11). GPlayed Trojan - .Net playing with Google Market . Retrieved November 24, 2020.
  5. Vitor Ventura. (2019, April 9). Gustuff banking botnet targets Australia . Retrieved September 3, 2019.
  6. R. Gevers, M. Tivadar, R. Bleotu, A. M. Barbatei, et al.. (2020, May 14). Uprooting Mandrake: The Story of an Advanced Android Spyware Framework That Went Undetected for 4 Years. Retrieved July 15, 2020.
  7. Proofpoint. (2017, November 3). Credential phishing and an Android banking Trojan combine in Austrian mobile attacks. Retrieved July 6, 2018.
  8. Blaich, A., et al. (2018, January 18). Dark Caracal: Cyber-espionage at a Global Scale. Retrieved April 11, 2018.
  9. J. Chandraiah. (2018, July 23). Red Alert 2.0: Android Trojan targets security-seekers. Retrieved December 14, 2020.
  10. Tatyana Shishkova. (2019, June 25). Riltok mobile Trojan: A banker with global reach. Retrieved August 7, 2019.
  11. T. Shishkova, L. Pikman. (2018, November 22). The Rotexy mobile Trojan – banker and ransomware. Retrieved September 23, 2019.
  12. Satori Threat Intelligence and Research Team. (2020, August). TERRACOTTA Android Malware: A Technical Study. Retrieved December 18, 2020.
  13. S. Desai. (2020, September 8). TikTok Spyware. Retrieved January 5, 2021.
  14. Cong Zheng, Claud Xiao and Zhi Xu. (2016, February 18). New Android Trojan “Xbot” Phishes Credit Cards and Bank Accounts, Encrypts Devices for Ransom. Retrieved December 21, 2016.
  15. Claud Xiao. (2015, September 18). Update: XcodeGhost Attacker Can Phish Passwords and Open URLs through Infected Apps. Retrieved December 21, 2016.