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Account Manipulation: Additional Cloud Roles
Other sub-techniques of Account Manipulation (5)
| ID | Name |
|---|---|
| T1098.001 | Additional Cloud Credentials |
| T1098.003 | Additional Cloud Roles |
An adversary may add additional roles or permissions to an adversary-controlled cloud account to maintain persistent access to a tenant. For example, adversaries may update IAM policies in cloud-based environments or add a new global administrator in Office 365 environments. With sufficient permissions, a compromised account can gain almost unlimited access to data and settings (including the ability to reset the passwords of other admins).
This account modification may immediately follow
Create Account [MITRE]
or other malicious account activity. Adversaries may also modify existing
Valid Accounts [MITRE]
that they have compromised. This could lead to privilege escalation, particularly if the roles added allow for lateral movement to additional accounts.
For example, in AWS environments, an adversary with appropriate permissions may be able to use the CreatePolicyVersion API to define a new version of an IAM policy or the AttachUserPolicy API to attach an IAM policy with additional or distinct permissions to a compromised user account.
In some cases, adversaries may add roles to adversary-controlled accounts outside the victim cloud tenant. This allows these external accounts to perform actions inside the victim tenant without requiring the adversary to
Create Account [MITRE]
or modify a victim-owned account.
AWS Specific Content
A prerequisite for this technique is that a threat actor has already gained control of an AWS identity with the permissions to perform the actions in the AWS CloudTrail Event Name(s) section.
With access to an AWS identity that has the appropriate permissions, threat actors may add IAM Roles to the AWS account or add IAM policies to identities that the threat actor has control over in order to provide persistent access to a threat actor, or alter the level and type of access previously granted.
Detection
Collect activity logs from IAM services and cloud administrator accounts to identify unusual activity in the assignment of roles to those accounts. Monitor for accounts assigned to admin roles that go over a certain threshold of known admins.AWS Specific Content
When this technique is used by the threat actor, actions taken by the threat actor using the credentials obtained will be logged in CloudTrail. You can use the Event History page in the AWS CloudTrail console to view the last 90 days of management events in an AWS Region for the events listed in the AWS CloudTrail Event Name(s) section, such as such as
iam:CreateRole.A separate CloudTrail trail will give you an ongoing record of events in your AWS account past 90 days and can be configured to log events in multiple regions. You can also review events using the console as well as the AWS CLI.
It is also possible to create a CloudWatch metric filter to watch for when specific AWS API calls are used and perform notification actions if logged, and additionally configure CloudWatch to automatically perform an action in response to an alarm.
If Amazon GuardDuty is configured within the AWS account, an IAMUser/AnomalousBehavior finding may be created if this technique is used (note - this finding can also be created for identities that add and then assume roles). This finding is presented in GuardDuty when actions commonly used to obtain additional permissions in an AWS environment were invoked in an anomalous way.
Mitigation
AWS Specific Content
You can make sure that principals are scoped with the least-privileged permissions necessary to perform duties, limiting the ability to perform unauthorized actions in an AWS account when not required. One possible method of applying the principle of least-privileged permissions is to use Service Control Policies to restrict the maximum available permissions for the IAM users and IAM roles within your AWS Organizations accounts (note - you should test SCPs in a development environment before deploying them in production).
You can also use IAM Access Analyzer to regularly review and verify access and manage permissions across your AWS environment, which will highlight AWS identities with excessive permissions and the actions performed by those identities.