Case Study 6: Cloud Migration Threat Modeling

A traditional enterprise undertaking cloud migration discovered that lift-and-shift approaches failed to address cloud-specific threats. Their journey illustrates how threat modeling must evolve with architectural changes.

Initial threat models simply mapped on-premises threats to cloud equivalents. This approach missed crucial cloud-specific issues: the shared responsibility model gaps, API-based attacks, and multi-tenancy risks. A security incident during pilot migration—thankfully contained to test data—prompted comprehensive cloud threat modeling.

The revised approach examined each application through a cloud lens. They discovered numerous issues: IAM roles with excessive permissions, data flows traversing multiple regions violating compliance requirements, and dependencies on cloud services not available in required regions. The threat model drove significant architectural changes beyond simple migration.

Particularly valuable was identifying "security regression" where cloud migration actually reduced security. For example, on-premises databases behind multiple firewalls became cloud databases protected only by security groups. The threat model ensured equivalent or better controls in the cloud architecture.

The organization developed a cloud threat modeling framework used across all migrations. This standardization accelerated subsequent migrations while ensuring consistent security. They estimate threat modeling added 10% to migration effort but prevented multiple potential breaches and compliance violations.