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ATM Network Penetration Testing & Risk Mitigation

Our Client’s Backstory

Our client is a European financial institution serving a retail base of over 100 million clients. Known for its digital innovation, the bank introduced "cardless" ATM features, allowing users to withdraw funds via mobile applications without a physical card or PIN. Recognizing that these features create new attack vectors, the bank’s leadership engaged Klika to conduct a penetration testing exercise to fortify their ATM network and protect against financial fraud.

The Challenges

Evaluating the security of a distributed ATM network required navigating architectural interdependencies and operational constraints. Key challenges included:

Evolving Attack Vectors: Assessing the vulnerability of "PIN-less" and "card-less" withdrawal features that bypass physical security layers.
Operational Continuity: Performing security testing without disrupting the bank’s daily global operations or interfering with customer transactions.
Network Segmentation: Ensuring the ATM infrastructure was isolated from the bank’s core network to prevent lateral movement during simulated attacks.
Third-Party Risk Management: Identifying security gaps introduced by external technology vendors and integrated third-party hardware components.
Methodological Precision: Architecting a testing strategy that complies with international financial regulations and cybersecurity standards.

Solutions

Klika was hired as a security consultant to lead the end-to-end penetration testing and risk assessment process. Our solution included:

OWASP-Based Audit Framework: Executed a security audit targeting the "OWASP Top 10" vulnerabilities, adhering to global financial industry guidelines.
Simulated Cyberattack Orchestration: Developed and deployed custom attack scripts to probe the ATM-to-server communication layer for authentication weaknesses.
Vulnerability Identification & Mapping: Performed a risk analysis, identifying high-severity vulnerabilities across code, architecture, and network configurations.
Remediation Strategy Development: Provided an actionable roadmap for mitigating threats, including the implementation of server-side OAUTH checks and Transport Layer Security (TLS) hardening.
API Security Hardening: Recommended the transition to enhanced HTTPS protocols for communications with external APIs and third-party service providers.
Continuous Monitoring & Alerting: Established an alert system to detect and flag suspicious activities across the ATM network during and after the testing phase.

The Results

The penetration testing exercise resulted in a fortification of the bank’s digital defenses, protecting both institutional assets and customer data.

Secured 100M+ Retail Clients: Successfully identified and remediated entry points that could have exposed millions of users to financial embezzlement.
Remediation of High-Severity Threats: Addressed critical vulnerabilities in the cardless withdrawal flow, preventing potential ATM network breaches.
Enhanced Institutional Trust: Reaffirmed the bank’s reputation as a secure financial service provider through proactive risk mitigation.
Optimized Security Posture: Provided the bank’s internal security teams with a data-driven benchmark for future cybersecurity investments.
Zero-Disruption Testing Execution: Completed the audit and remediation phase with no impact on the bank’s 24/7 global service availability.