Hi!

Two weeks ago, I had the pleasure to give a talk for the Global Azure 2022 – Quebec City Chapter about the Cloud Security Training.

Maxime.

Hi!

In this article, I will show you how you can scan an Azure Blob to identity potential public storage containers. By default when you create a new container, you have 3 options to define the public level access:

• Private: No public access to this container (default configuration).
• Blob: Public access is permitted to this container and its blobs.
• Container: Public access is permitted to blobs in this container, but not to the container itself.

To leverage this attack, we will use a function including in the MicroBurst tool.

Invoke-EnumerateAzureBlobs -Base yourcompanyname

In this example, I will use an additional containerlist file with some folders examples (dev, non, prod, devprod, ….)

Invoke-EnumerateAzureBlobs -Base zigmaxlab -Folders .\containerlist.txt

Maxime.

Hi!

Attackers want to target service principals because:

• Service accounts and service principals do not have MFA
• Attackers can log into Azure using a service principal account
• These accounts exist with all applications in Azure (most companies have several) 
• These accounts could be controlled through conditional access only with an Azure Active Directory P2.

Sign-in with the service principal using Azure CLI:

az login –service-principal -u YourServicePrincipald -p YourServicePrincipalPassword -tenant YourTenantId –allow-no-subscriptions

To prevent this attack, you can define a Conditional Access policies for your service principals. You need to have an Azure Active Directory Premium P2 to enable this feature.

• https://docs.microsoft.com/en-us/azure/active-directory/conditional-access/workload-identity
• https://docs.microsoft.com/en-us/azure/active-directory/conditional-access/howto-conditional-access-policy-location

Maxime.