Executive Summary

A leading national private bank is the 5th largest bank in Indonesia by assets, offering a full range of financial services including retail banking, corporate banking, and digital banking solutions. As a tech-forward institution, the bank is a pioneer in cloud adoption among Indonesian banks and continues to lead innovation through its award-winning digital banking platforms. To support secure cloud adoption, the bank partnered with an Mastersystem Infotama Managed Security Service Provider (MSSP) to ensure continuous monitoring, compliance readiness, and proactive threat response across its AWS environments.

Challange

The bank cloud expansion strategy introduced several security and operational challenges:

• • Regulatory Demands: Must meet strict requirements from OJK (Indonesia Financial Services Authority), Bank Indonesia, and ISO 27001, including log retention, segmentation, and auditability.
• • Growing Attack Surface: Expansion of services on AWS increased the complexity and risk of misconfiguration or targeted attacks.
• • Internal SOC Overload: The internal Security Operations Center (SOC) required support to manage cloud-native threats and 24/7 monitoring.
• • Multi-Account Complexity: AWS accounts used for dev and production across business units needed centralized governance.

Solution

The bank engages with Mastersystem MSSP with the following key implementations:

Result and Benefit

Through the collaboration with an Mastersystem MSSP, the bank achieved tangible improvements across its cloud security operations and regulatory alignment, such as:

• • The implementation of continuous threat detection and response led to a significant improvement in incident handling. The MSSP successfully detected and responded to 98% of known threats within defined SLA with a mean time to detect (MTTD) of and a mean time to respond (MTTR) just in minutes. This allowed the bank to move from a reactive to a proactive security posture.
• • As a result of ongoing security hardening and posture assessments, the bank saw a 47% reduction in critical security incidents in the first-time engagement indicating stronger preventive controls and faster mitigation cycles.
• • In terms of compliance, the Mastersystem MSSP reporting and automation significantly reduced manual efforts. The time required to prepare for regulatory audits such as those mandated by OJK and ISO 27001 was reduced by 65%, streamlining communication with internal risk teams and external auditors.
• • Security visibility across cloud assets also improved dramatically. By integrating services like AWS Config, Security Hub, and CloudTrail into a centralized dashboard, the bank achieved 100% visibility across all AWS accounts and workloads.
• • Log management was optimized to meet financial regulatory requirements. The MSSP handled secure ingestion, retention, and access control of log data per month, ensuring integrity and availability for compliance and forensics purposes.
• • Finally, the bank AWS Security Hub posture score increased to 92% indicating a measurable improvement in cloud security maturity and governance across all environments.