Adversaries may add adversary-controlled credentials to a cloud account to maintain persistent access to victim accounts and instances within the environment.
For example, adversaries may add credentials for Service Principals and Applications in addition to existing legitimate credentials in Azure AD. These credentials include both x509 keys and passwords. With sufficient permissions, there are a variety of ways to add credentials including the Azure Portal, Azure command line interface, and Azure or Az PowerShell modules.
In infrastructure-as-a-service (IaaS) environments, after gaining access through Cloud Accounts, adversaries may generate or import their own SSH keys using either the
ImportKeyPair API in AWS or the
gcloud compute os-login ssh-keys add command in GCP. This allows persistent access to instances within the cloud environment without further usage of the compromised cloud accounts.
Adversaries may also use the
CreateAccessKey API in AWS or the
gcloud iam service-accounts keys create command in GCP to add access keys to an account. If the target account has different permissions from the requesting account, the adversary may also be able to escalate their privileges in the environment (i.e. Cloud Accounts). For example, in Azure AD environments, an adversary with the Application Administrator role can add a new set of credentials to their application's service principal. In doing so the adversary would be able to access the service principal’s roles and permissions, which may be different from those of the Application Administrator.
In AWS environments, adversaries with the appropriate permissions may also use the
sts:GetFederationToken API call to create a temporary set of credentials tied to the permissions of the original user account. These credentials may remain valid for the duration of their lifetime even if the original account’s API credentials are deactivated.
During C0027, Scattered Spider used aws_consoler to create temporary federated credentials for fake users in order to obfuscate which AWS credential is compromised and enable pivoting from the AWS CLI to console sessions without MFA.
Use multi-factor authentication for user and privileged accounts. Consider enforcing multi-factor authentication for the
Configure access controls and firewalls to limit access to critical systems and domain controllers. Most cloud environments support separate virtual private cloud (VPC) instances that enable further segmentation of cloud systems.
|Privileged Account Management
Do not allow domain administrator or root accounts to be used for day-to-day operations that may expose them to potential adversaries on unprivileged systems.
|User Account Management
Ensure that low-privileged user accounts do not have permission to add access keys to accounts. In AWS environments, prohibit users from calling the
|User Account Modification
Monitor for unexpected changes to cloud user accounts, such as Azure Activity Logs highlighting malicious Service Principal and Application modifications.
Monitor for the use of API and CLI commands that add access keys or tokens to accounts, such as