Privilege Escalation

Adversaries may manipulate accounts to maintain and/or elevate access to victim systems. Account manipulation may consist of any action that preserves or modifies adversary access to a compromised account, such as modifying credentials or permission groups. These actions could also include account activity designed to subvert security policies, such as performing iterative password updates to bypass password duration policies and preserve the life of compromised credentials.

In order to create or manipulate accounts, the adversary must already have sufficient permissions on systems or the domain. However, account manipulation may also lead to privilege escalation where modifications grant access to additional roles, permissions, or higher-privileged Valid Accounts [MITRE] .

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 [MITRE] , adversaries may generate or import their own SSH keys using either the CreateKeyPair or 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 [MITRE] ). 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 principals 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 to Forge Web Credentials [MITRE] tied to the permissions of the original user account. These temporary credentials may remain valid for the duration of their lifetime even if the original accounts API credentials are deactivated.

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.

Adversaries may modify the configuration settings of a domain or identity tenant to evade defenses and/or escalate privileges in centrally managed environments. Such services provide a centralized means of managing identity resources such as devices and accounts, and often include configuration settings that may apply between domains or tenants such as trust relationships, identity syncing, or identity federation.

Modifications to domain or tenant settings may include altering domain Group Policy Objects (GPOs) in Microsoft Active Directory (AD) or changing trust settings for domains, including federation trusts relationships between domains or tenants.

With sufficient permissions, adversaries can modify domain or tenant policy settings. Since configuration settings for these services apply to a large number of identity resources, there are a great number of potential attacks malicious outcomes that can stem from this abuse. Examples of such abuse include:

* modifying GPOs to push a malicious Scheduled Task [MITRE] to computers throughout the domain environment * modifying domain trusts to include an adversary-controlled domain, allowing adversaries to forge access tokens that will subsequently be accepted by victim domain resources * changing configuration settings within the AD environment to implement a Rogue Domain Controller [MITRE] . * adding new, adversary-controlled federated identity providers to identity tenants, allowing adversaries to authenticate as any user managed by the victim tenant

Adversaries may temporarily modify domain or tenant policy, carry out a malicious action(s), and then revert the change to remove suspicious indicators.

Adversaries may add new domain trusts, modify the properties of existing domain trusts, or otherwise change the configuration of trust relationships between domains and tenants to evade defenses and/or elevate privileges.Trust details, such as whether or not user identities are federated, allow authentication and authorization properties to apply between domains or tenants for the purpose of accessing shared resources. These trust objects may include accounts, credentials, and other authentication material applied to servers, tokens, and domains.

Manipulating these trusts may allow an adversary to escalate privileges and/or evade defenses by modifying settings to add objects which they control. For example, in Microsoft Active Directory (AD) environments, this may be used to forge SAML Tokens [MITRE] without the need to compromise the signing certificate to forge new credentials. Instead, an adversary can manipulate domain trusts to add their own signing certificate. An adversary may also convert an AD domain to a federated domain using Active Directory Federation Services (AD FS), which may enable malicious trust modifications such as altering the claim issuance rules to log in any valid set of credentials as a specified user.

An adversary may also add a new federated identity provider to an identity tenant such as Okta or AWS IAM Identity Center, which may enable the adversary to authenticate to any user of the tenant. This may enable the threat actor to gain broad access into a variety of cloud-based services that leverage the identity tenant. For example, in AWS environments, an adversary that creates a new identity provider for an AWS Organization will be able to federate into all of the AWS Organization member accounts without creating identities for each of the member accounts.

Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network. Adversaries may choose not to use malware or tools in conjunction with the legitimate access those credentials provide to make it harder to detect their presence.

In some cases, adversaries may abuse inactive accounts: for example, those belonging to individuals who are no longer part of an organization. Using these accounts may allow the adversary to evade detection, as the original account user will not be present to identify any anomalous activity taking place on their account.

The overlap of permissions for local, domain, and cloud accounts across a network of systems is of concern because the adversary may be able to pivot across accounts and systems to reach a high level of access (i.e., domain or enterprise administrator) to bypass access controls set within the enterprise.