T1110.003Password Spraying

Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials. Password spraying uses one password (e.g. 'Password01'), or a small list of commonly used passwords, that may match the complexity policy of the domain. Logins are attempted with that password against many different accounts on a network to avoid account lockouts that would normally occur when brute forcing a single account with many passwords. (Citation: BlackHillsInfosec Password Spraying) Typically, management services over commonly used ports are used when password spraying. Commonly targeted services include the following: * SSH (22/TCP) * Telnet (23/TCP) * FTP (21/TCP) * NetBIOS / SMB / Samba (139/TCP & 445/TCP) * LDAP (389/TCP) * Kerberos (88/TCP) * RDP / Terminal Services (3389/TCP) * HTTP/HTTP Management Services (80/TCP & 443/TCP) * MSSQL (1433/TCP) * Oracle (1521/TCP) * MySQL (3306/TCP) * VNC (5900/TCP) In addition to management services, adversaries may "target single sign-on (SSO) and cloud-based applications utilizing federated authentication protocols," as well as externally facing email applications, such as Office 365.(Citation: US-CERT TA18-068A 2018) In default environments, LDAP and Kerberos connection attempts are less likely to trigger events over SMB, which creates Windows "logon failure" event ID 4625.