Multicloud Security for Leading Financial Institution

The Multicloud Security Challenge

Project Context

Tier-one financial institutions operate in increasingly complex cloud ecosystems. This project addressed one of the sector’s most significant challenges: consistently and efficiently securing multiple cloud environments while maintaining strict regulatory compliance required by the Spanish and European financial sector.

Initial Complexity

Cloud Providers in Scope:

• Microsoft Azure: Primary workloads and Microsoft 365
• Google Cloud Platform: Advanced analytics and BigQuery
• Oracle Cloud Infrastructure: Legacy systems and critical databases
• IBM Cloud: Modernized mainframe applications

Identified Issues:

• 4 different security consoles without correlation
• 847 inconsistent security policies across providers
• 23 security tools with functional overlap
• Average detection time: 4.2 hours
• East-west traffic visibility gap

Unified Security Architecture

Cloud Governance Framework

Layer 1: Federated Policies Development of security control catalog mapped to:

• CIS Benchmarks (Azure, GCP, OCI)
• Spanish financial regulation (Bank of Spain)
• DORA (Digital Operational Resilience Act)
• PCI-DSS v4.0

Layer 2: Centralized Visibility

┌─────────────────────────────────────────────────────────┐
│                   Centralized SIEM                       │
│              (Microsoft Sentinel + Chronicle)            │
├─────────────────────────────────────────────────────────┤
│  Azure Logs  │  GCP Logs  │  OCI Logs  │  IBM Logs     │
│  Defender    │  Chronicle │  Cloud     │  QRadar       │
│  for Cloud   │  Security  │  Guard     │  Integration  │
└─────────────────────────────────────────────────────────┘

Layer 3: Automated Response Unified response playbooks operating cross-cloud:

• Automatic isolation of compromised workloads
• Credential revocation across all providers
• Escalation based on asset criticality

Cloud Security Posture Management

Continuous Assessment:

• Configuration scanning every 15 minutes
• Automatic drift detection
• Integrated remediation workflows
• Real-time compliance scoring

Posture Metrics:

• Unified Security Score: 94/100
• Critical misconfigurations: 0 (from 234 initial)
• Compliance gaps: 2% (from 34% initial)

Results and Metrics

Detection Improvement

Metric	Before	After	Improvement
MTTD (Mean Time to Detect)	4.2 hours	23 minutes	91%
MTTR (Mean Time to Respond)	6.8 hours	45 minutes	89%
False Positive Rate	67%	12%	82%
Asset Coverage	62%	99.7%	61%

Regulatory Compliance

Frameworks Achieved:

• PCI-DSS v4.0: 100% controls
• DORA: 98% readiness
• ENS High: Certification obtained
• GDPR: Demonstrated compliance

This project established a reference model for multicloud security in the Spanish financial sector, demonstrating that high security standards can be maintained while leveraging the flexibility of multiple cloud providers.