T1078: Valid 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.

Positive Technologies products that cover the technique

MaxPatrol SIEM knowledge base

kaspersky: PT-CR-744: Kaspersky_Endpoint_Policy_Modification: A Kaspersky Endpoint Security policy is changed it_bastion: PT-CR-2173: SKDPUNT_Unusual_Access: Abnormal account or system usage by a user it_bastion: PT-CR-2182: SKDPUNT_Unusual_User_Activity: SKDPU NT detected activity of a long unused account it_bastion: PT-CR-2176: SKDPUNT_Session_From_Different_Subnet: Session of a user from another subnet it_bastion: PT-CR-2175: SKDPUNT_Unusual_User_Activity_Time: Abnormal user activity time sap_attack_detection: PT-CR-161: SAPASABAP_Using_Various_Accounts_On_One_Terminal: Usage of different accounts on the one host from the same source sap_attack_detection: PT-CR-159: SAPASABAP_Trying_Get_Privileges: An attempt to escalate privileges in SAP sap_attack_detection: PT-CR-163: SAPASABAP_Wrong_User_Type: Using wrong user type for login attempts in SAP system mysql_database: PT-CR-624: MySQL_Permissions_Operation: Attempt to change account permissions mysql_database: PT-CR-625: MySQL_User_Operation: Attempt to change or delete a user account zabbix: PT-CR-2047: Zabbix_Logon_Same_User_From_Different_Terminals: A user logged in to Zabbix several times from different hosts. This could be an attacker's attempt to escalate privileges. zabbix: PT-CR-2049: Zabbix_Logon_Different_Users_On_Same_Terminal: A user logged in to Zabbix under multiple accounts. This could be an attacker's attempt to gain initial access or persistence in the system, escalate privileges, or bypass protection. zabbix: PT-CR-2044: Zabbix_Logon_Of_Significant_User: A blacklisted user logged in to Zabbix. This could be an attacker's attempt to escalate privileges or bypass protection. sap_java_suspicious_user_activity: PT-CR-539: SAPASJAVA_Logon_Of_Significant_User: A user logged in under a blacklisted account sap_java_suspicious_user_activity: PT-CR-538: SAPASJAVA_Failed_Logon_With_Locked_Expired_User: Multiple failed attempts to log in are detected sap_java_suspicious_user_activity: PT-CR-540: SAPASJAVA_Logon_Success_Same_User_From_Different_Terminals: Multiple successful attempts to log in from different terminals are detected sap_suspicious_user_activity: PT-CR-230: SAPASABAP_Assigning_Yourself_Privileges: A user assigned himself privileges in the system sap_suspicious_user_activity: PT-CR-250: SAPASABAP_Login_Fired_Employee: A dismissed employee logged in to the system sap_suspicious_user_activity: PT-CR-256: SAPASABAP_Unlock_Login_And_Lock_User: Suspicious user activity in SAP sap_suspicious_user_activity: PT-CR-239: SAPASABAP_Fast_Login_Logoff: Abnormal behavior of a user in the system bruteforce: PT-CR-906: LyncSmash_Use: Bruteforcing attempts for Skype accounts using LyncSmash security_code_secret_net_lsp: PT-CR-1886: SecretNet_LSP_Logon_Of_Significant_User: A blacklisted user logged in to the system postgresql_database: PT-CR-2334: PostgreSQL_Assignment_Sensitive_Privilege: Assigning sensitive privileges may result in escalation of root privileges

Subtechniques

Detection

IDDS0028Data source and componentLogon Session: Logon Session CreationDescription

Monitor for newly constructed logon behavior that may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Correlate other security systems with login information (e.g., a user has an active login session but has not entered the building or does not have VPN access).

IDDS0002Data source and componentUser Account: User Account AuthenticationDescription

Monitor for an attempt by a user that may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion.

IDDS0028Data source and componentLogon Session: Logon Session MetadataDescription

Look for suspicious account behavior across systems that share accounts, either user, admin, or service accounts. Examples: one account logged into multiple systems simultaneously; multiple accounts logged into the same machine simultaneously; accounts logged in at odd times or outside of business hours. Activity may be from interactive login sessions or process ownership from accounts being used to execute binaries on a remote system as a particular account.

Mitigation

IDM1013NameApplication Developer GuidanceDescription

Ensure that applications do not store sensitive data or credentials insecurely. (e.g. plaintext credentials in code, published credentials in repositories, or credentials in public cloud storage).

IDM1015NameActive Directory ConfigurationDescription

Disable legacy authentication, which does not support MFA, and require the use of modern authentication protocols instead.

IDM1017NameUser TrainingDescription

Applications may send push notifications to verify a login as a form of multi-factor authentication (MFA). Train users to only accept valid push notifications and to report suspicious push notifications.

IDM1018NameUser Account ManagementDescription

Regularly audit user accounts for activity and deactivate or remove any that are no longer needed.

IDM1026NamePrivileged Account ManagementDescription

Audit domain and local accounts as well as their permission levels routinely to look for situations that could allow an adversary to gain wide access by obtaining credentials of a privileged account. These audits should also include if default accounts have been enabled, or if new local accounts are created that have not be authorized. Follow best practices for design and administration of an enterprise network to limit privileged account use across administrative tiers.

IDM1027NamePassword PoliciesDescription

Applications and appliances that utilize default username and password should be changed immediately after the installation, and before deployment to a production environment. When possible, applications that use SSH keys should be updated periodically and properly secured.

Policies should minimize (if not eliminate) reuse of passwords between different user accounts, especially employees using the same credentials for personal accounts that may not be defended by enterprise security resources.

IDM1036NameAccount Use PoliciesDescription

Use conditional access policies to block logins from non-compliant devices or from outside defined organization IP ranges.