CHAIN-092 — Cross-region replication to unauthorised region

Summary

Severity: Medium · Likelihood: Low · Logic: ALL

Why this chain matters

A storage account is configured for GRS to a region outside the tenant's data residency commitments. A compliance auditor flags this as a data-sovereignty breach — but operationally the data is also reachable from the secondary region, doubling the attack surface.

Component rules

This chain fires when its trigger conditions are met by the following rules. Click any rule to see its detection logic and compliance mappings.

Rule ID	Role
zt_data_009	Trigger
zt_data_010	Trigger

Attack walkthrough

Step 1 — GRS writes continuous copies to a non-approved region.

Actor: Compliance failure
MITRE ATT&CK: T1537
Enabled by: zt_data_009

Attacker gain: Data residing outside contractual region.

Step 2 — Compromise the secondary endpoint; same content as primary.

Actor: Regional attacker
MITRE ATT&CK: T1530
Enabled by: zt_data_010

Attacker gain: Data in a harder-to-monitor region.

Blast radius

Initial access	Secondary-region attack path.
Max privilege	Read on replicated blobs.
Data at risk	Same as primary
Services at risk	Cross-region storage

How the logic works

The chain fires only when every rule above has at least one finding in the current scan. Missing any one rule breaks the chain — so remediating any single step disrupts the attack path.