NTLMv1 Logon Between Client and Server

calendar Apr 28, 2026 · attack.lateral-movement attack.t1550.002  ·
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Detects the reporting of NTLMv1 being used between a client and server. NTLMv1 is insecure as the underlying encryption algorithms can be brute-forced by modern hardware.

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 1title: NTLMv1 Logon Between Client and Server
 2id: e9d4ab66-a532-4ef7-a502-66a9e4a34f5d
 3status: test
 4description: Detects the reporting of NTLMv1 being used between a client and server. NTLMv1 is insecure as the underlying encryption algorithms can be brute-forced by modern hardware.
 5references:
 6    - https://github.com/nasbench/EVTX-ETW-Resources/blob/f1b010ce0ee1b71e3024180de1a3e67f99701fe4/ETWProvidersManifests/Windows10/22H2/W10_22H2_Pro_20230321_19045.2728/WEPExplorer/LsaSrv.xml
 7author: Tim Shelton, Nasreddine Bencherchali (Nextron Systems)
 8date: 2022-04-26
 9modified: 2023-06-06
10tags:
11    - attack.lateral-movement
12    - attack.t1550.002
13logsource:
14    product: windows
15    service: system
16detection:
17    selection:
18        Provider_Name: "LsaSrv"
19        EventID:
20            - 6038
21            - 6039
22    condition: selection
23falsepositives:
24    - Environments that use NTLMv1
25level: medium

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