Detect Password Policy Discovery in Google Chronicle
Adversaries may attempt to access detailed information about the password policy used within an enterprise network or cloud environment. Password policies enforce complexity requirements that make passwords harder to guess or crack through brute force. By discovering lockout thresholds, minimum length, and complexity rules, adversaries can tailor dictionary and brute force attacks to comply with the policy — maximizing credential testing while avoiding account lockout. Discovery occurs via command-line utilities (net accounts, Get-ADDefaultDomainPasswordPolicy, chage, pwpolicy), cloud APIs (AWS GetAccountPasswordPolicy), and network device CLIs. This technique is commonly observed in the early reconnaissance phase of intrusions by groups including OilRig, Turla, and Chimera.
MITRE ATT&CK
- Tactic
- Discovery
- Technique
- T1201 Password Policy Discovery
- Canonical reference
- https://attack.mitre.org/techniques/T1201/
YARA-L Detection Query
rule t1201_password_policy_discovery {
meta:
author = "Argus Detection Engineering"
description = "Detects Password Policy Discovery (T1201) via process execution of net accounts, PowerShell AD cmdlets, chage, pwpolicy, NtdsAudit, or CrackMapExec password policy enumeration."
mitre_attack_tactic = "Discovery"
mitre_attack_technique = "T1201"
severity = "MEDIUM"
priority = "MEDIUM"
events:
$e.metadata.event_type = "PROCESS_LAUNCH"
$e.principal.process.file.full_path != ""
(
// net.exe accounts or net1.exe accounts
(re.regex($e.principal.process.file.full_path, `(?i)(net\.exe|net1\.exe)$`) and
re.regex($e.principal.process.command_line, `(?i)accounts`))
or
// PowerShell AD password policy cmdlets
(re.regex($e.principal.process.file.full_path, `(?i)(powershell\.exe|pwsh\.exe)$`) and
re.regex($e.principal.process.command_line, `(?i)(Get-ADDefaultDomainPasswordPolicy|Get-ADFineGrainedPasswordPolicy|Get-ADFineGrainedPasswordPolicySubject|Get-PassPol)`))
or
// NtdsAudit utility
re.regex($e.principal.process.command_line, `(?i)NtdsAudit`)
or
// CrackMapExec-style password policy flags
re.regex($e.principal.process.command_line, `(?i)(--pass-pol|--password-policy)`)
or
// Linux chage -l / --list
(re.regex($e.principal.process.file.full_path, `(?i)chage$`) and
re.regex($e.principal.process.command_line, `(?i)(-l\b|--list)`))
or
// macOS pwpolicy getaccountpolicies
(re.regex($e.principal.process.file.full_path, `(?i)pwpolicy$`) and
re.regex($e.principal.process.command_line, `(?i)getaccountpolicies`))
)
condition:
$e
}Chronicle YARA-L 2.0 rule detecting T1201 Password Policy Discovery. Matches PROCESS_LAUNCH UDM events where command-line arguments indicate enumeration of password policy settings using native OS utilities or common offensive security tools.
Data Sources
Required Tables
False Positives & Tuning
- Privileged IT staff running Get-ADDefaultDomainPasswordPolicy as part of regular Active Directory audits or compliance checks
- Security assessment tools (e.g., PingCastle, BloodHound) querying AD password policy during authorized assessments
- Linux system administrators using chage -l to review user account aging settings for compliance
Other platforms for T1201
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Local Password Policy Discovery via net accounts
Expected signal: Sysmon Event ID 1: Process Create with Image ending in net.exe or net1.exe, CommandLine='net accounts'. Security Event ID 4688 (if command line auditing is enabled) with same details. Parent process will be cmd.exe or the calling shell.
- Test 2Domain Password Policy Discovery via net accounts /domain
Expected signal: Sysmon Event ID 1: Process Create with Image=net.exe, CommandLine='net accounts /domain'. Net.exe internally calls net1.exe which also generates a process creation event. The query contacts the PDC emulator — Sysmon Event ID 3 (Network Connect) may show a connection to the DC on port 445 or 135.
- Test 3Domain Password Policy via PowerShell Get-ADDefaultDomainPasswordPolicy
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe, CommandLine containing 'Get-ADDefaultDomainPasswordPolicy'. PowerShell ScriptBlock Log Event ID 4104 capturing the full command. Sysmon Event ID 7 (Image Load) may show Microsoft.ActiveDirectory.Management.dll being loaded.
- Test 4Linux Password Policy Discovery via PAM configuration
Expected signal: On systems with auditd: syscall audit records for openat()/read() on /etc/security/pwquality.conf and /etc/pam.d/common-password (auditd rule: -w /etc/pam.d/ -p r -k pam_policy_read). Process creation event for chage with -l argument. On MDE Linux agent: DeviceProcessEvents event for chage with ProcessCommandLine containing '-l'.
References (13)
- https://attack.mitre.org/techniques/T1201/
- https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/net-accounts
- https://docs.aws.amazon.com/IAM/latest/APIReference/API_GetAccountPasswordPolicy.html
- https://superuser.com/questions/150675/how-to-display-password-policy-information-for-a-user-ubuntu
- https://www.jamf.com/jamf-nation/discussions/18574/user-password-policies-on-non-ad-machines
- https://www.us-cert.gov/ncas/alerts/TA18-106A
- https://github.com/clymb3r/PowerShell/blob/master/Get-PassHashes/Get-PassHashes.ps1
- https://github.com/byt3bl33d3r/CrackMapExec
- https://github.com/nettitude/PoshC2
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1201/T1201.md
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_net_password_policy_discovery.yml
- https://www.fireeye.com/blog/threat-research/2017/12/targeted-attack-in-middle-east-by-apt34.html
- https://research.nccgroup.com/2021/01/12/abusing-cloud-services-to-fly-under-the-radar/
Unlock Pro Content
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