Gustuff

Gustuff is mobile malware designed to steal users' banking and virtual currency credentials.[1]

ID: S0406
Type: MALWARE
Platforms: Android
Version: 1.0

Techniques Used

Domain ID Name Use
Mobile T1432 Access Contact List

Gustuff can collect the contact list. [1]

Mobile T1438 Alternate Network Mediums

Gustuff can use SMS for command and control from a defined admin phone number. [1]

Mobile T1418 Application Discovery

Gustuff checks for antivirus software contained in a predefined list.[1]

Mobile T1412 Capture SMS Messages

Gustuff can intercept two-factor authentication codes transmitted via SMS. [1]

Mobile T1533 Data from Local System

Gustuff can capture files and photos from the compromised device. [1]

Mobile T1476 Deliver Malicious App via Other Means

Gustuff was distributed via SMS phishing messages to numbers exfiltrated from compromised devices’ contact lists. The phishing SMS messages are sent from the compromised device to the target device.[1]

Mobile T1417 Input Capture

Gustuff abuses accessibility features to intercept all interactions between a user and the device.[1]

Mobile T1516 Input Injection

Gustuff injects the global action GLOBAL_ACTION_BACK to mimic pressing the back button to close the application if a call to an open antivirus application is detected.[1]

Mobile T1411 Input Prompt

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.[1][2]

Mobile T1406 Obfuscated Files or Information

Gustuff code is both obfuscated and packed with an FTT packer. Command information is obfuscated using a custom base85-based encoding.[1]

Mobile T1437 Standard Application Layer Protocol

Gustuff communicates with the command and control server using HTTP requests.[1]

Mobile T1508 Suppress Application Icon

Gustuff hides its icon after installation. [2]

Mobile T1426 System Information Discovery

Gustuff gathers information about the device, including the default SMS application, if SafetyNet is enabled, the battery level, the operating system version, and if the malware has elevated permissions.[1]

Mobile T1422 System Network Configuration Discovery

Gustuff gathers the device IMEI to send to the command and control server.[1]

References