Full Report
Uncover the disruptive nature of Gigabud malware and take proactive measures to mitigate the associated risks
Analysis Summary
# Tool/Technique: Gigabud (Gigabud RAT / Gigabud.Loan)
## Overview
Gigabud is a disruptive Android banking trojan and Remote Access Trojan (RAT) designed to defraud users primarily in the APAC and LATAM regions. It masquerades as legitimate government agencies or financial institutions (often via fake loan applications) to steal sensitive financial information, record screens, and bypass two-factor authentication (2FA).
## Technical Details
- **Type:** Malware family (Banking Trojan / RAT)
- **Platform:** Android
- **Capabilities:** Screen recording, accessibility service abuse, keylogging, data exfiltration, and 2FA bypass.
- **First Seen:** Approximately mid-2022 (variants continue to evolve).
## MITRE ATT&CK Mapping
- **[TA0037 - Persistence]**
- [T1624.001 - Event Notification: Accessibility Service]
- **[TA0035 - User Execution]**
- [T1204.001 - Malicious Link]
- **[TA0009 - Collection]**
- [T1513 - Screen Capture]
- [T1417.001 - Input Capture: Keylogging]
- **[TA0006 - Credential Access]**
- [T1411 - Input Injection] (Overlay attacks)
- **[TA0011 - Command and Control]**
- [T1071.001 - Web Protocols: HTTP]
## Functionality
### Core Capabilities
- **Accessibility Service Abuse:** Requests permissions to monitor user actions, read screen content, and interact with other apps autonomously.
- **Credential Theft:** Uses fake login pages and overlays to harvest banking credentials and personal identification information.
- **Screen Recording:** Captures real-time screen activity to steal sensitive data that might not be captured via standard keylogging.
- **Data Exfiltration:** Sends harvested device information, SMS messages, and contact lists to a remote C2 server.
### Advanced Features
- **RAT Functionality:** Allows attackers to remotely control the device to perform actions as the user, facilitating unauthorized fund transfers.
- **Bypassing 2FA:** By reading SMS messages and notifications, the malware can intercept one-time passwords (OTPs) to bypass security measures.
- **Masquerading:** Specifically targets users by impersonating tax authorities, social security offices, or regional bank apps to build false trust.
## Indicators of Compromise
- **File Hashes:** *(Note: Specific hashes vary by campaign; check latest threat feeds for current SHA256 values)*
- **File Names:** Often uses names mimicking government apps, e.g., "Government_Service.apk," "Loan_App.apk," or localized versions in Thai, Vietnamese, or Spanish.
- **Network Indicators:**
- `http[:]//[random-subdomain].gigabud[.]com` (Defanged)
- `http[:]//[C2-IP-Address]/admin/api/` (Defanged)
- **Behavioral Indicators:**
- Repeated requests for "Accessibility Services" permissions.
- Unusual battery drain or data usage.
- Presence of unrecognized overlay windows on top of banking applications.
## Associated Threat Actors
- Unknown (Current research suggests financially motivated cybercriminal groups operating within or targeting the APAC and LATAM regions).
## Detection Methods
- **Signature-based detection:** Implementation of MD5/SHA256 hashes in EDR and mobile security suites.
- **Behavioral detection:** Monitoring for apps that request Accessibility Services and immediately begin high-volume data transmission or screen scraping.
- **YARA rules:** Detection rules targeting specific strings within the Android Manifest and DEX files related to Gigabud's unique C2 communication patterns.
## Mitigation Strategies
- **Prevention measures:** Only download applications from the official Google Play Store; disable "Install from Unknown Sources."
- **Hardening recommendations:**
- Strictly audit Accessibility Service permissions.
- Implement mobile threat defense (MTD) solutions.
- Use biometric authentication where possible, as it is harder to spoof via RAT than PINs/Passwords.
- **Incident Response:** If infected, disable network access, freeze bank accounts immediately, and perform a factory reset of the device.
## Related Tools/Techniques
- **Godfather:** Another Android banking trojan with similar overlay and C2 capabilities.
- **Anubis:** A well-known predecessor in the Android banking malware space.
- **Smishing (SMS Phishing):** The primary delivery mechanism for Gigabud links.