Password Policy Discovery

What the technique is

Adversaries may attempt to access detailed information about the password policy used within an enterprise network or cloud environment. Password policies are a way to enforce complex passwords that are difficult to guess or crack through Brute Force. This information may help the adversary to create a list of common passwords and launch dictionary and/or brute force attacks which adheres to the policy (e.g. if the minimum password length should be 8, then not trying passwords such as 'pass123'; not checking for more than 3-4 passwords per account if the lockout is set to 6 as to not lock out accounts). Password policies can be set and discovered on Windows, Linux, and macOS systems via various command shell utilities such as net accounts (/domain), Get-ADDefaultDomainPasswordPolicy, chage -l, cat /etc/pam.d/common-password, and pwpolicy getaccountpolicies. Adversaries may also leverage a Network Device CLI on network devices to discover password policy information (e.g. show aaa, show aaa common-criteria policy all). Password policies can be discovered in cloud environments using available APIs such as GetAccountPasswordPolicy in AWS.

What MITRE says you would watch

• AN0455

  Cause→effect chain: (1) a user or service spawns a shell/PowerShell that queries local/domain password policy via commands/cmdlets (e.g., net accounts, Get-ADDefaultDomainPasswordPolicy, secedit /export); (2) optional directory/LDAP reads from DCs; (3) same principal performs adjacent Discovery or credential-related actions within a short window. Correlate sysmon process creation with PowerShell ScriptBlock and Security logs.

• AN0456

  Chain: (1) interactive/non-interactive chage -l, grep/cat of PAM config (e.g., /etc/pam.d/common-password, /etc/security/pwquality.conf); (2) optional reads of /etc/login.defs; (3) same user performs account enumeration or password change attempts shortly after. Use auditd execve and file read events plus shell history collection.

• AN0457

  Chain: (1) execution of pwpolicy or MDM/DirectoryService reads of account policies; (2) optional read of /Library/Preferences/com.apple.loginwindow or config profiles; (3) follow-on credential probing or lateral movement by same user/session. Use unified logs and process telemetry.