Detect Use Alternate Authentication Material in CrowdStrike LogScale
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/
LogScale Detection Query
// T1550 — Use Alternate Authentication Material
// Detects Pass-the-Hash, Pass-the-Ticket, and NTLM hash override via Falcon sensor telemetry
// Note: Falcon does not forward raw Windows event logs; correlate with UserLogon and AuthActivity events
#repo=base_sensor_telemetry
(
// Pass-the-Hash detection via UserLogon events — LogonType 9 NewCredentials
(
#event_simpleName=UserLogon
LogonType=9
| eval AttackPattern="Pass-the-Hash: LogonType 9 NewCredentials (mimikatz sekurlsa::pth)"
| eval SuspicionScore=3
)
OR
// Pass-the-Hash via NTLM network logon (LogonType 3)
(
#event_simpleName=UserLogon
LogonType=3
AuthenticationPackage=NTLM
NOT RemoteAddressIP4 IN ("127.0.0.1", "")
NOT UserName = /.*\$$/
| eval AttackPattern="Pass-the-Hash: NTLM Network Logon from Remote Source"
| eval SuspicionScore=1
)
OR
// Pass-the-Ticket via Kerberos RC4 downgrade
(
#event_simpleName=KerberosServiceTicket
TicketEncryptionType=0x17
| eval AttackPattern="Pass-the-Ticket: RC4-HMAC Kerberos Downgrade (Golden/Silver Ticket)"
| eval SuspicionScore=2
)
OR
// NTLM credential validation failure — hash override attempt
(
#event_simpleName=NTLMv2Login
Status != "0x0"
Status != ""
| eval AttackPattern="NTLM Hash Override: Credential Validation Failure"
| eval SuspicionScore=1
)
)
| groupBy(
[ComputerName, UserName, RemoteAddressIP4, LogonType, AuthenticationPackage,
TicketEncryptionType, Status, AttackPattern, SuspicionScore],
function=count(as=EventCount))
| sort(SuspicionScore, order=desc)CrowdStrike Falcon LogScale (CQL) detection for Use of Alternate Authentication Material (T1550). Queries Falcon sensor telemetry for UserLogon events with LogonType 9 (definitive Pass-the-Hash artifact), NTLM network logons (LogonType 3), Kerberos RC4 downgrade tickets, and NTLM validation failures. Groups results by host and user for triage. Supplement with Windows Security Event log ingestion via Falcon LogScale connector for full Event 4769/4776 coverage.
Data Sources
Required Tables
False Positives & Tuning
- Falcon UserLogon LogonType 9 events generated by legitimate runas /netonly commands used by administrators to run tools with alternate domain credentials without local logon
- NTLM LogonType 3 events from CrowdStrike RTR (Real Time Response) sessions or Falcon sensor health-check mechanisms authenticating over the network
- KerberosServiceTicket RC4 events from older Falcon-protected hosts running Windows Server 2008 R2 or earlier where AES Kerberos is not enforced by Group Policy
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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