Find sigma rule 
Attack: Brute Force: Password Guessing
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts. Without knowledge of the password for an account, an adversary may opt to systematically guess the password using a repetitive or iterative mechanism. An adversary may guess login credentials without prior knowledge of system or environment passwords during an operation by using a list of common passwords. Password guessing may or may not take into account the target’s policies on password complexity or use policies that may lock accounts out after a number of failed attempts.
Guessing passwords can be a risky option because it could cause numerous authentication failures and account lockouts, depending on the organization’s login failure policies. (Citation: Cylance Cleaver)
Typically, management services over commonly used ports are used when guessing passwords. 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)
- SNMP (161/UDP and 162/TCP/UDP)
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). Further, adversaries may abuse network device interfaces (such as wlanAPI) to brute force accessible wifi-router(s) via wireless authentication protocols.(Citation: Trend Micro Emotet 2020)
In default environments, LDAP and Kerberos connection attempts are less likely to trigger events over SMB, which creates Windows “logon failure” event ID 4625.
MITRE
Tactic
- credential-access
technique
- T1110.001
Test : SUDO Brute Force - Redhat
OS
- linux
Description:
An adversary may find themselves on a box (e.g. via ssh key auth, with no password) with a user that has sudo’ers privileges, but they do not know the users password. Normally, failed attempts to access root will not cause the root account to become locked, to prevent denial-of-service. This functionality enables an attacker to undertake a local brute force password guessing attack without locking out the root user.
This test creates the “art” user with a password of “password123”, logs in, downloads and executes the sudo_bruteforce.sh which brute force guesses the password, then deletes the user
Executor
bash