CHAIN-137 — VM extension custom script contains embedded password

Summary

Severity: Medium · Likelihood: Medium · Logic: ALL

Why this chain matters

A VM is provisioned with a custom-script extension that passes credentials as script arguments. Anyone with Reader on the VM can view the extension's settings including plaintext args. No secret rotation, no history.

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_wl_024	Trigger
zt_wl_028	Trigger

Attack walkthrough

Step 1 — View VM extension settings via ARM API.

Actor: Reader
MITRE ATT&CK: T1552.001
Enabled by: zt_wl_024

Attacker gain: Plaintext credential in extension args.

Step 2 — Use credential to authenticate elsewhere.

Actor: Attacker
MITRE ATT&CK: T1078
Enabled by: zt_wl_028

Attacker gain: Follow-on access.

Blast radius

Initial access	Reader role.
Max privilege	Whatever cred grants.
Data at risk	Downstream systems
Services at risk	Wherever the cred is valid

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.