Strategy and Solutions
Our client was a regional credit union serving over 350,000 customers across multiple states in the U.S. The firm had recently completed a major digital transformation initiative, including launching a new online and mobile banking platform. The leadership team understood that modernization improved customer convenience and expanded the organization’s attack surface.
To safeguard member assets and comply with FFIEC cybersecurity guidelines, the credit union engaged Zymr to perform a comprehensive penetration testing and social engineering assessment before the platform’s official launch.
This engagement was critical because financial institutions face some of the highest fraud risks per transaction value. The goal was to identify and fix vulnerabilities that could result in economic loss, regulatory scrutiny, or reputational damage before attackers could exploit them.
High-Value Attack Surface
The credit union’s new digital banking environment included customer-facing web apps, mobile APIs, and integrations with third-party payment gateways. The interconnections between legacy core banking systems and modern web layers created complex security boundaries.
Authentication Weaknesses
During initial reviews, Zymr noted that the authentication design relied heavily on static credentials and session tokens without adaptive checks or rate limits, making brute-force and credential-stuffing attacks plausible.
Internal Network Exposure
The DMZ and internal networks were not properly segmented. Several shared administrative accounts could bridge external application servers to core banking databases, posing an elevated risk of lateral movement.
Human Factor Risks
Employees represented another critical vector. The institution had previously rolled out phishing training but never tested real-world susceptibility under controlled conditions.
The combination of digital expansion, legacy dependencies, and human risk created the perfect storm for potential fraud. Zymr’s challenge was to uncover and help neutralize these weak points before criminals could.
The environment was typical of many fast-growing financial institutions, modern interfaces sitting atop old infrastructure, stitched together by trust. Testing it meant validating not just code, but culture, configuration, and process discipline.
The penetration testing engagement delivered measurable improvements across the client’s environment.
These results gave both executives and regulators confidence in the credit union’s ability to manage cybersecurity risk in a complex, evolving digital landscape.
The impact was immediate: fewer exploitable surfaces, better-prepared employees, and a tested incident response muscle that proved itself when real attackers came knocking.
The engagement’s ripple effect went beyond patches and passwords, institutionalized vigilance. Security became part of how the bank thought, not just what it fixed.
Zymr helped the regional credit union transform its digital banking launch from a potential vulnerability into a success story. By uncovering and resolving weaknesses before criminals could exploit them, the institution prevented potential multi-million-dollar fraud losses and gained lasting credibility with customers, auditors, and regulators alike.
The case also demonstrated how modern penetration testing is not about “finding holes” but about creating resilience through continuous testing, human awareness, and measurable follow-up.
Today, the credit union’s platform serves hundreds of thousands of users securely. Its leadership continues to cite this engagement as the pivotal turning point in establishing cybersecurity as a business enabler, not a cost center.
Zymr’s penetration testing engagement combined external, internal, and social engineering assessments, executed over a 10-week engagement period using real-world attacker methodologies under controlled, ethical conditions.
1. External Penetration Testing
We began with black-box reconnaissance to simulate how an external attacker might approach the public-facing assets. Key findings included:
Our team responsibly exploited the authentication flaw to demonstrate unauthorized session reuse and then documented the full exploit chain, including how an attacker could capture a session token and escalate privileges.
Remediation involved implementing multi-factor authentication (MFA), regenerating session tokens upon privilege elevation, and enforcing API gateway validation policies.
2. Internal Network Testing
After obtaining controlled access through the staging VPN, our red team pivoted to simulate an insider or compromised device scenario.
Zymr recommended microsegmentation using identity-based network controls, implementation of least-privilege policies, and automated patch management with validation SLAs.
3. Social Engineering Assessment
Our social engineering team executed both phishing and vishing (phone-based) campaigns across departments.
Following disclosure, Zymr conducted awareness workshops, designed new simulated phishing scenarios, and integrated mandatory adaptive training based on employee roles.
4. Security Hardening & Validation
Post-remediation, Zymr conducted validation testing to confirm that all critical findings were addressed. MFA was verified across channels, network segmentation rules were stress-tested, and employee phishing resilience improved by 62% after three months of follow-up training.
The engagement wasn’t a one-time audit was a partnership to create a more resilient, security-aware financial ecosystem that combined technology, governance, and human readiness.
Zymr’s layered approach turned vulnerabilities into learning points. Each weakness uncovered became a blueprint for stronger policies and infrastructure, making security measurable, teachable, and repeatable.
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