Detect Use Alternate Authentication Material in Google Chronicle
Adversaries may use alternate authentication material, such as password hashes, Kerberos tickets, and application access tokens, in order to move laterally within an environment and bypass normal system access controls. Authentication processes generally require a valid identity (e.g., username) along with one or more authentication factors (e.g., password, pin, physical smart card, token generator, etc.). Alternate authentication material is legitimately generated by systems after a user or application successfully authenticates by providing a valid identity and the required authentication factor(s). By stealing alternate authentication material, adversaries are able to bypass system access controls and authenticate to systems without knowing the plaintext password or any additional authentication factors. Sub-techniques include Application Access Token abuse (T1550.001), Pass the Hash (T1550.002), Pass the Ticket (T1550.003), and Web Session Cookie reuse (T1550.004).
MITRE ATT&CK
- Tactic
- Defense Evasion Lateral Movement
- Canonical reference
- https://attack.mitre.org/techniques/T1550/
YARA-L Detection Query
rule T1550_use_alternate_authentication_material {
meta:
author = "Argus Detection Engineering"
description = "Detects Use of Alternate Authentication Material (T1550): Pass-the-Hash via LogonType 9 or remote NTLM logon (Event 4624), Pass-the-Ticket via RC4 Kerberos downgrade (Event 4769), and NTLM hash override attempts (Event 4776)"
mitre_attack_tactic = "Lateral Movement"
mitre_attack_technique = "T1550"
mitre_attack_subtechniques = "T1550.002, T1550.003"
severity = "HIGH"
confidence = "HIGH"
reference = "https://attack.mitre.org/techniques/T1550/"
version = "1.0"
events:
$e.metadata.product_name = "Microsoft-Windows-Security-Auditing"
$e.metadata.event_type = "USER_LOGIN"
(
// Pass-the-Hash: LogonType 9 NewCredentials — definitive mimikatz sekurlsa::pth indicator
(
$e.metadata.product_event_type = "4624"
and $e.extensions.auth.auth_details = "9"
)
or
// Pass-the-Hash: NTLM network logon from non-local source
(
$e.metadata.product_event_type = "4624"
and $e.extensions.auth.auth_details = "3"
and re.regex($e.network.application_protocol, `(?i)ntlm`)
and $e.principal.ip != ""
and not $e.principal.ip in ("127.0.0.1", "::1")
and not re.regex($e.target.user.userid, `.*\$$`)
)
or
// Pass-the-Ticket: RC4-HMAC Kerberos encryption downgrade
(
$e.metadata.product_event_type = "4769"
and re.regex($e.extensions.auth.auth_details, `0x17|0x18|23`)
and $e.security_result.summary = "0x0"
)
or
// NTLM Hash Override: credential validation failure
(
$e.metadata.product_event_type = "4776"
and $e.security_result.summary != ""
and not re.regex($e.security_result.summary, `^(0x0|0|-)$`)
)
)
$e.principal.hostname = $hostname
condition:
$e
}Chronicle YARA-L 2.0 rule detecting Use of Alternate Authentication Material (T1550) using UDM event model. Monitors Windows Security event type USER_LOGIN for Pass-the-Hash indicators (LogonType 9, NTLM remote network logons), Pass-the-Ticket RC4 Kerberos downgrade, and NTLM hash credential validation failures. Maps to MITRE ATT&CK T1550 Lateral Movement.
Data Sources
Required Tables
False Positives & Tuning
- NTLM LogonType 3 authentications from legitimate remote desktop gateway or jump server solutions that proxy NTLM credentials across network segments
- Kerberos service ticket requests using RC4 encryption (0x17) from third-party applications or services with constrained delegation configured for legacy encryption
- NTLM validation failure events (4776) generated by monitoring tools or SIEM health-check accounts probing domain controller authentication endpoints
Other platforms for T1550
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 1Pass-the-Hash via Mimikatz sekurlsa::pth (Windows)
Expected signal: Sysmon Event ID 1: Process Create for mimikatz.exe with parent process context. Security Event ID 4624 with LogonType=9, TargetUserName=testadmin, AuthenticationPackageName=NTLM on the local host — this fires immediately when the new process token is created. If the spawned cmd.exe then accesses a network resource, Security Event ID 4624 LogonType=3 with NTLM auth will appear on the target host. Sysmon Event ID 10 may appear if mimikatz accessed LSASS.
- Test 2Pass-the-Hash via Impacket wmiexec.py (Linux attacking Windows)
Expected signal: On the target Windows host: Security Event ID 4624 with LogonType=3, AuthenticationPackageName=NTLM, IpAddress=<Linux attacker IP>, TargetUserName=testadmin. Security Event ID 4688 (or Sysmon Event ID 1) showing WmiPrvSE.exe spawning cmd.exe for the WMI command execution. No LogonType 9 event — this is a pure NTLM Type 3 network logon, demonstrating the PTH_NTLM detection branch.
- Test 3Pass-the-Ticket — Export and Inject Kerberos Ticket via Mimikatz
Expected signal: Sysmon Event ID 1: Process Create for mimikatz.exe. After ticket injection, subsequent Kerberos service ticket requests from the session may appear in Security Event ID 4769 — if the injected ticket is RC4-encrypted (common with older tickets or those from tools using RC4), TicketEncryptionType=0x17 will appear. Security Event ID 4648 may appear when using the injected ticket to access network resources. klist output shows the injected service ticket.
- Test 4Overpass-the-Hash — Convert NTLM Hash to Kerberos TGT via Mimikatz /ptt
Expected signal: Security Event ID 4624 LogonType=9 on the local host when the new credential token is created. Security Event ID 4768 (Kerberos TGT request) on the domain controller showing the AS-REQ using RC4-HMAC encryption (TicketEncryptionType=0x17) if the domain does not enforce AES-only. Security Event ID 4769 when the TGT is used to request service tickets for SYSVOL/CIFS access. The combination of LogonType 9 followed by Kerberos tickets from that session ties the PTH origin to subsequent Kerberos activity.
References (13)
- https://attack.mitre.org/techniques/T1550/
- https://technet.microsoft.com/en-us/library/dn487457.aspx
- https://csrc.nist.gov/glossary/term/authentication
- https://csrc.nist.gov/glossary/term/multi_factor_authentication
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-securityevent-table
- https://github.com/gentilkiwi/mimikatz/wiki/module-~-sekurlsa
- https://github.com/SecureAuthCorp/impacket
- https://www.sans.org/white-papers/36962/
- https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/plan/security-best-practices/credential-protection-and-management
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1550.002/T1550.002.md
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1550.003/T1550.003.md
- https://adsecurity.org/?p=1515
- https://www.microsoft.com/en-us/security/blog/2021/09/27/foggyweb-targeted-nobelium-malware-leads-to-persistent-backdoor/
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