GUI Input Capture

GUI Input Capture [T1056.002]

Information

• Name: GUI Input Capture

• ID: T1056.002

• Tactics: TA0009, TA0006

• Technique: T1056

Introduction

GUI Input Capture (T1056.002) is a sub-technique within the MITRE ATT&CK framework under the broader Input Capture technique (T1056). It involves adversaries capturing user inputs by intercepting graphical user interface (GUI) interactions, such as mouse clicks, keystrokes, and screen captures. Attackers typically leverage this sub-technique to gain sensitive information, credentials, or confidential data entered by users into applications or web interfaces. Unlike traditional keylogging, GUI Input Capture focuses specifically on interactions with graphical elements, making it particularly effective against virtual keyboards or other techniques designed to evade standard keyloggers.

Deep Dive Into Technique

GUI Input Capture primarily involves intercepting and recording user interactions with graphical interfaces. Technical execution methods include:

• Hooking APIs and DLL Injection:

  • Attackers inject malicious code into running processes to hook graphical interface APIs, such as Windows' user32.dll or GDI (Graphics Device Interface) functions, enabling them to intercept and log user interactions.

  • DLL injection allows attackers to seamlessly integrate their malicious payload into legitimate processes, making detection challenging.

• Screen Capturing and Image Recognition:

  • Attackers periodically take screenshots or continuously record the user’s screen activity, capturing sensitive information entered via virtual keyboards or graphical interfaces.

  • Advanced malware may process these images using optical character recognition (OCR) techniques, extracting sensitive text data from screenshots.

• Event Logging via GUI Frameworks:

  • Malware may leverage built-in GUI framework capabilities (e.g., Windows message loops, Qt event handling, or Java Swing listeners) to log user interactions directly from the application interface.

• Accessibility Features Exploitation:

  • Attackers abuse built-in accessibility APIs (e.g., Windows Accessibility API, MacOS Accessibility API) intended to assist users with disabilities, allowing them to intercept GUI interactions without raising suspicion.

Real-world procedures typically involve stealthy malware deployment, often delivered through phishing emails, malicious attachments, compromised websites, or software supply chain compromises.

When this Technique is Usually Used

Attackers commonly use GUI Input Capture in various attack scenarios and stages, including:

• Credential Harvesting:

  • Capturing login credentials entered through graphical interfaces, particularly in sensitive environments such as banking portals, corporate VPNs, or remote desktop sessions.

• Espionage and Information Theft:

  • Recording interactions with sensitive documents, proprietary software interfaces, or confidential databases to obtain intellectual property or classified information.

• Initial Access and Privilege Escalation:

  • Monitoring administrative credentials or sensitive interactions by privileged users to escalate privileges or gain persistent access.

• Bypassing Security Measures:

  • Capturing inputs from virtual keyboards or secure input fields designed to prevent traditional keylogging techniques.

• Targeted Attacks and Advanced Persistent Threats (APTs):

  • Used extensively by sophisticated threat actors to remain undetected and continuously monitor high-value targets.

How this Technique is Usually Detected

Detection of GUI Input Capture involves a combination of behavioral analysis, endpoint monitoring, and anomaly detection. Common detection methods include:

• Endpoint Detection and Response (EDR) tools:

  • Monitoring processes for suspicious hooking or DLL injection behavior.

  • Detecting unauthorized access to GUI-related DLLs and APIs (e.g., user32.dll, GDI32.dll).

• Behavioral Analysis and Heuristics:

  • Identifying unusual patterns of screen capturing activity (e.g., frequent screenshots, unusual screen recording processes).

  • Detecting processes accessing accessibility APIs without legitimate reasons.

• Application Whitelisting and Integrity Checks:

  • Ensuring only authorized applications interact with GUI frameworks and accessibility APIs.

  • Monitoring for unauthorized modifications or injections into legitimate GUI processes.

• Network Traffic Analysis:

  • Identifying unusual outbound traffic patterns indicative of exfiltrated GUI-captured data (e.g., image files, OCR-extracted text data).

• Indicators of Compromise (IoCs):

  • Suspicious DLLs or executables injected into GUI processes.

  • Unusual file artifacts (e.g., periodic screen captures saved as image files).

  • Suspicious registry entries or scheduled tasks related to unknown GUI monitoring tools.

  • Logs showing unauthorized access or hooking of GUI-related APIs.

Why it is Important to Detect This Technique

Detecting GUI Input Capture is crucial due to its potentially severe impacts on systems, networks, and organizational security:

• Credential Theft and Account Compromise:

  • Attackers gain access to sensitive credentials and authentication tokens, enabling further exploitation, lateral movement, or privilege escalation.

• Data Leakage and Intellectual Property Theft:

  • Sensitive information, corporate secrets, proprietary data, or classified documents can be exfiltrated, causing significant financial and reputational damage.

• Persistence and Advanced Threat Activity:

  • GUI Input Capture often indicates advanced persistent threats (APTs) or sophisticated attackers attempting to remain undetected within the environment for prolonged periods.

• Compliance and Regulatory Violations:

  • Failure to detect and prevent GUI Input Capture can lead to violations of data protection regulations (e.g., GDPR, HIPAA), resulting in legal repercussions and heavy fines.

• Reduced Trust and Operational Disruption:

  • Successful exploitation can severely impact user trust, disrupt business operations, and require costly remediation efforts.

Early detection significantly reduces potential damage, facilitates timely incident response, and mitigates long-term impacts on organizational security.

Examples

Real-world examples and attack scenarios involving GUI Input Capture include:

• Banking Trojans (e.g., Zeus, SpyEye):

  • These malware families frequently leverage GUI Input Capture techniques to intercept credentials entered via virtual keyboards on banking websites, bypassing traditional keylogging detection mechanisms.

  • Attackers use captured credentials to access victim accounts, initiate fraudulent transactions, and cause financial losses.

• APT28 (Fancy Bear) and Espionage Campaigns:

  • APT28 has used sophisticated GUI Input Capture methods to monitor user interactions, capture sensitive information, and exfiltrate classified documents from government entities, diplomatic institutions, and defense contractors.

  • Malware deployed by APT28 often injects code into legitimate processes, intercepting GUI interactions without raising suspicion.

• DarkHotel APT:

  • DarkHotel attackers have employed GUI Input Capture to intercept sensitive data from high-profile targets staying in luxury hotels, capturing credentials and confidential information entered via graphical interfaces on compromised hotel Wi-Fi networks.

• Remote Access Trojans (RATs) (e.g., njRAT, DarkComet):

  • Many RATs include built-in GUI Input Capture capabilities, allowing attackers to remotely monitor victim screens, intercept graphical inputs, and exfiltrate sensitive information.

• FIN7 Cybercrime Group:

  • FIN7 has used GUI Input Capture techniques in targeted attacks against retail, hospitality, and restaurant sectors, capturing payment card details and credentials entered via graphical point-of-sale (POS) interfaces.

In each scenario, attackers leverage GUI Input Capture to bypass traditional security defenses, obtain sensitive data, and achieve their malicious objectives with minimal detection risk.