Unveiling Crocodilus: The Advanced Mobile Banking Trojan Threat

TL;DR

The Crocodilus Android Trojan exploits accessibility features to steal banking and crypto credentials, primarily targeting users in Spain and Turkey. This sophisticated malware uses advanced techniques like remote control and black screen overlays, posing a significant threat to mobile security.

The New Android Trojan: Crocodilus

ThreatFabric researchers have identified a new Android Trojan called Crocodilus, which exploits accessibility features to steal banking and crypto credentials. This malware is not a simple clone but a fully-fledged threat equipped with modern techniques such as remote control, black screen overlays, and advanced data harvesting via accessibility logging¹.

Key Features of Crocodilus

Crocodilus mimics modern banking malware, employing overlay attacks, keylogging, and remote access. Notably, it bypasses Android 13+ restrictions via a dropper. The malware connects to a Command and Control (C2) server, monitors app launches, and uses overlays to steal credentials. Although it primarily targets users in Spain and Turkey, global expansion is expected¹.

Bot Capabilities

• Call & SMS Control: Enables call forwarding, sends SMS to specified numbers or all contacts, retrieves SMS messages, and makes itself the default SMS manager.
• Overlay Attacks: Checks for available overlays targeting installed applications, typically for credential theft.
• Device Administration & Persistence: Requests Device Admin privileges, locks the screen, and protects itself from deletion.
• Notifications & Social Engineering: Posts fake push notifications to trick users.
• Remote Commands & Settings Updates: Updates bot and C2 settings, enables/disables sound, and handles task execution¹.

RAT Capabilities

• Screen Interaction & Control: Performs swipes, clicks, and button presses (Back, Home, Menu).
• Hidden RAT Mode: Can enable “hidden” remote access while muting the phone and displaying a black overlay to conceal activities.
• Data Theft: Captures Google Authenticator screen content to steal OTP codes.
• Camera Access: Starts front camera streaming for potential identity theft or surveillance¹.

Advanced Data Theft Techniques

Crocodilus steals OTP codes from Google Authenticator via Accessibility Logging, enabling account takeovers. It also uses hidden remote access with a black screen overlay and muted sound to conceal fraudulent activities. The malware tricks victims into revealing their seed phrase by displaying a fake warning, then logs the text via Accessibility features to steal and drain crypto wallets¹.

Potential Links to Known Threat Actors

The malware may be linked to the threat actor “sybra,” known for using Ermac forks and other malware. The analysis of the source code suggests its authors are Turkish-speaking².

Conclusion

The emergence of the Crocodilus mobile banking Trojan marks a significant escalation in the sophistication and threat level posed by modern malware. With its advanced device-takeover capabilities, remote control features, and the deployment of black overlay attacks from its earliest iterations, Crocodilus demonstrates a level of maturity uncommon in newly discovered threats. Already observed targeting banks in Spain and Turkey and popular cryptocurrency wallets, Crocodilus is clearly engineered to go after high-value assets¹.

For further insights, check:

• ThreatFabric Report on Crocodilus
• Security Affairs on Ermac Banking Trojan

References

1. ThreatFabric (2025). “Exposing Crocodilus: New Device-Takeover Malware Targeting Android Devices”. ThreatFabric. Retrieved 2025-03-29. ↩︎ ↩︎² ↩︎³ ↩︎⁴ ↩︎⁵ ↩︎⁶

2. Security Affairs (2025). “Ermac Banking Trojan”. Security Affairs. Retrieved 2025-03-29. ↩︎