Financial services organizations are prime targets for sophisticated cybercriminals seeking to steal sensitive financial data and conduct fraudulent transactions. SecureBank International, a multinational banking institution with assets exceeding $50 billion, discovered an advanced persistent threat (APT) campaign that had maintained covert access to their systems for over eight months. This case study examines how we conducted a comprehensive threat hunt and implemented advanced security measures to eliminate the threat and prevent future incidents.
Background
SecureBank International operates in 25 countries, providing corporate banking, wealth management, and investment services to high-net-worth clients. The institution maintained robust perimeter security but lacked advanced threat detection capabilities for insider threats and sophisticated attack campaigns. The APT group had gained initial access through a spear-phishing campaign targeting senior executives and had established persistent access through living-off-the-land techniques that evaded traditional security controls.
Discovery of the APT Campaign
The threat was initially discovered through anomalous behavior detection:
- Unusual patterns in privileged account usage during off-hours.
- Subtle changes in file access patterns for high-value customer accounts.
- Encrypted communication channels established through legitimate business applications.
- Gradual escalation of privileges across multiple departments over several months.
Threat Hunting and Digital Forensics
Our incident response team conducted an extensive threat hunting operation to understand the full scope of the compromise.
Advanced Threat Analysis
The investigation revealed sophisticated tactics, techniques, and procedures (TTPs):
- Living-off-the-Land Techniques – Attackers used legitimate administrative tools and PowerShell scripts to avoid detection by traditional antivirus solutions.
- Credential Harvesting – Systematic collection of privileged credentials through memory dumping and keystroke logging on executive workstations.
- Data Staging and Exfiltration – Customer financial data was compressed and staged in legitimate file sharing locations before being exfiltrated through encrypted channels.
Comprehensive Incident Response
The response required coordination across multiple time zones and business units while maintaining business continuity.
Threat Eradication and Recovery
Our team executed a coordinated response to eliminate the threat:
Simultaneous Credential Reset – All privileged accounts were simultaneously reset across the global infrastructure to prevent re-entry through compromised credentials.
Advanced Persistent Threat Removal – Custom tools were developed to detect and remove APT implants and backdoors that had been established throughout the network.
Enhanced Monitoring Deployment – Next-generation SIEM and user behavior analytics were deployed to detect similar attack patterns and prevent future APT campaigns.
Outcome and Business Impact
The successful APT response strengthened SecureBank’s security posture while maintaining customer trust:
Complete Threat Elimination – All APT artifacts were successfully removed with no evidence of ongoing unauthorized access or data exfiltration.
Regulatory Compliance – Full cooperation with financial regulators resulted in no penalties despite the significant nature of the incident.
Enhanced Security Maturity – Implementation of advanced threat detection capabilities reduced mean time to detection from months to hours for similar attack patterns.
