Travelex Ransomware Attack 2020: Essential Cyber Security Lessons for UK Accountants

On New Year's Eve 2019, Travelex—one of the world's largest foreign exchange companies—fell victim to a devastating REvil ransomware attack. The breach paralysed operations across 30 countries for nearly three weeks, cost the company £25 million, and ultimately contributed to its collapse into administration. For UK SME accounting firms holding similarly sensitive client financial data, the Travelex incident serves as a stark warning about the catastrophic consequences of inadequate ransomware defences.

The Attack Timeline: How the Breach Unfolded

31 December 2019 – The Attack Begins

The REvil ransomware gang (also known as Sodinokibi) infiltrated Travelex's network by exploiting an unpatched vulnerability in the company's Pulse Secure VPN appliance (CVE-2019-11510). Despite a security patch being available since April 2019, Travelex had failed to apply the critical update, leaving a gaping security hole that attackers exploited to gain initial access.

1 January 2020 – Discovery and Shutdown

Travelex discovered the breach when ransomware began encrypting files across its systems. The company immediately took its entire network offline—including customer-facing websites and backend systems used by major banking partners like Barclays, HSBC, Royal Bank of Scotland, Sainsbury's Bank, and Tesco Bank. The shutdown prevented customers from making currency exchanges online and forced high street branches to revert to manual, paper-based processes.

2-21 January 2020 – Extended Downtime and Ransom Demands

For three weeks, Travelex's systems remained offline whilst forensic investigators worked to contain the breach and assess the damage. REvil demanded an initial ransom of £4.6 million (later reportedly increased to £18 million) and threatened to publish 5GB of stolen customer data on the dark web, including dates of birth, payment card information, and national insurance numbers. The prolonged outage cost Travelex an estimated £300,000 per day in lost revenue and operational disruption.

22 January 2020 – Services Gradually Restored

After nearly three weeks of downtime, Travelex began gradually restoring services. The company claimed no customer data had been accessed, though REvil disputed this assertion and published sample files as "proof" of data exfiltration—a classic double-extortion tactic increasingly used by ransomware gangs.

August 2020 – Administration and Collapse

The attack's financial impact proved insurmountable. Combined with the COVID-19 pandemic's devastating effect on international travel, Travelex entered administration in August 2020. Over 1,300 jobs were lost in the UK, and the company's retail operations were wound down. The once-global foreign exchange giant was dismantled—a stark example of how a single cyber security failure can destroy an established business.

Technical Analysis: How the Attack Succeeded

Vulnerability Exploitation (CVE-2019-11510)

The REvil ransomware gang exploited an unpatched Pulse Secure VPN vulnerability that allowed attackers to bypass authentication and gain remote code execution capabilities. Critically, Travelex had failed to apply the security patch released eight months earlier—a fundamental failure in vulnerability management that is alarmingly common in SME accounting practices as well.

"The Travelex attack demonstrates that ransomware gangs specifically target organisations with poor patch management. For accounting firms holding sensitive client financial data, the consequences of similar vulnerabilities could be catastrophic."

— Michael Thompson, Head of Incident Response, ProtekCyber

Lateral Movement and Privilege Escalation

Once inside Travelex's network, the attackers used legitimate administrative tools and exploited weak access controls to move laterally across systems, eventually gaining domain administrator privileges. This allowed them to disable backup systems, delete shadow copies, and deploy ransomware across the entire IT infrastructure simultaneously—maximising disruption and preventing recovery.

Data Exfiltration and Double Extortion

Before deploying the ransomware payload, REvil exfiltrated approximately 5GB of sensitive customer data to use as leverage in their double-extortion strategy. This tactic—now standard practice amongst sophisticated ransomware gangs—ensures that even organisations with robust backups face pressure to pay ransoms to prevent data publication.

Why This Matters for UK SME Accounting Firms

You might be thinking: "We're a small accounting practice, not a multi-national foreign exchange company. Why does Travelex's collapse matter to us?"

The answer is that UK accounting firms face identical ransomware risks, just on a different scale. Consider the parallels:

UK Regulatory Consequences for Accountants

Under UK GDPR, accounting firms face similar regulatory exposure. The Information Commissioner's Office (ICO) can impose fines up to £17.5 million or 4% of annual global turnover—whichever is higher. Additionally, professional bodies like ICAEW, ACCA, and CIMA can impose disciplinary sanctions for failing to protect client confidentiality, potentially including suspension or removal from practice.

Why ProtekCyber is the Leader in Protecting UK Accounting Firms from Ransomware

ProtekCyber specialises in defending UK SME accounting practices against the exact attack vectors that devastated Travelex. Our comprehensive ransomware protection framework addresses each stage of the attack lifecycle—from initial access prevention to rapid incident response and recovery.

Proactive Vulnerability Management

Travelex's failure to patch CVE-2019-11510 was the root cause of its collapse. ProtekCyber provides continuous vulnerability scanning and prioritised patch management for accounting firms, ensuring critical security updates are applied before attackers can exploit them. Our monthly vulnerability assessments identify and remediate security gaps in practice management software, VPN appliances, and cloud accounting platforms.

Immutable Backup and Rapid Recovery

Traditional backup systems failed Travelex because attackers encrypted them alongside production systems. ProtekCyber implements immutable, air-gapped backups specifically designed to survive ransomware attacks. Our backup solution includes:

• Daily automated backups of all critical accounting data
• Immutable storage that prevents modification or deletion by ransomware
• Offline air-gapped copies isolated from network attacks
• Rapid restoration capabilities (typically under 4 hours for critical systems)
• Quarterly disaster recovery testing to ensure backup viability

24/7 SOC Monitoring with Ransomware Detection

Travelex discovered the breach only after ransomware began encrypting files—far too late for effective containment. ProtekCyber's Security Operations Centre (SOC) monitors UK accounting firms 24/7 for early indicators of ransomware activity, including unusual file access patterns, suspicious PowerShell execution, and attempted lateral movement. When threats are detected, our incident response team can be activated within 15 minutes to contain the attack before ransomware deployment.

Ransomware Incident Response Retainer

When ransomware strikes, rapid response is critical. ProtekCyber provides accounting firms with pre-paid incident response retainers, ensuring immediate access to forensic investigators, legal counsel, and PR support. Our response playbooks include UK GDPR breach notification templates, ICO reporting guidance, and professional indemnity insurer liaison—all designed to minimise regulatory penalties and protect professional reputation.

Key Lessons and Immediate Action Steps

Based on our analysis of the Travelex ransomware attack, UK accounting firms should take these immediate protective measures:

Technical Controls

• Patch Management: Implement rigorous vulnerability scanning and prioritised patching, especially for VPN and remote access systems
• Multi-Factor Authentication: Enforce MFA on all remote access points, cloud accounting platforms, and administrative accounts
• Immutable Backups: Replace traditional backup systems with immutable, air-gapped solutions tested quarterly
• Network Segmentation: Isolate critical client data from general business systems to limit ransomware spread
• Endpoint Detection and Response: Deploy advanced threat detection on all devices accessing client data

Organisational Measures

• Incident Response Planning: Develop and test ransomware-specific response playbooks including client notification procedures
• Cyber Insurance: Ensure adequate coverage for ransomware incidents, including forensic investigation and regulatory fines
• Security Awareness Training: Train staff to recognise phishing emails and suspicious file attachments
• Regular DR Testing: Conduct quarterly disaster recovery exercises to validate backup restoration procedures