Query: alert when Detects the use of curl with NTLM authentication and empty credentials (-u :), which can be abused to leak the currently
Matching passage: Sigma rule: Detects the use of curl with NTLM authentication and empty credentials (-u :), which can be abused to leak the currently. Logsource: windows / process_creation. Rule: title: NTLM Hash Leak Via Curl NTLM Authentication id: 916eb839-895e-47f8-99ee-3008bf377a3e status: test description: 'Detects the use of curl with NTLM authentication and empty credentials (-u :), which can be abused to leak the currently logged-in user''s NTLMv2 challenge-response to an attacker-controlled server, enabling offline cracking or relay attacks. When no credentials are provided, the Microsoft-shipped curl passes a NULL identity to Windows SSPI, which automatically falls back to the current user''s logon session credentials stored in LSASS — without requiring a plaintext password. This behavior is exclusive to the curl binary shipped by Microsoft (available since Windows 10 / Windows Server 2019), which is built with SSPI support. ' references: - https://github.com/curl/curl/blob/master/lib/vauth/ntlm_sspi.c#L128-L140 - https://learn.microsoft.com/en-us/windows/win32/secauthn/acquirecredentialshandle--ntlm - https://curl.se/docs/manpage.html#--ntlm author: Swachchhanda Shrawan Poudel (Nextron Systems) date: 2026-06-04 tags: - attack.credential-access - attack.t1187 logsource: category: process_creation product: windows detection: selection_img: - Image|endswith: \curl.exe - OriginalFileName: curl.exe selection_ntlm_flag: CommandLine|contains: --ntlm selection_empty_creds: CommandLine|re: '(?i)\s(-u|--user)\s*:' condition: all of selection_* falsepositives: - Should be very rare as it's not widely known or used, but could occur in legitimate use cases where curl is used with NTLM authentication and empty credentials, such as in certain scripts or automation tasks. level: high regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_curl_ntlm_hash_leak_attempt/info.yml
Near-miss passage: Sigma rule: Detects important or interesting Windows services that got terminated for whatever reason. Logsource: windows / system. Rule: title: Important Windows Service Terminated With Error id: d6b5520d-3934-48b4-928c-2aa3f92d6963 related: - id: acfa2210-0d71-4eeb-b477-afab494d596c type: similar status: test description: Detects important or interesting Windows services that got terminated for whatever reason references: - https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/ author: Nasreddine Bencherchali (Nextron Systems) date: 2023-04-14 tags: - attack.stealth logsource: product: windows service: system detection: selection_eid: Provider_Name: Service Control Manager EventID: 7023 selection_name: - param1|contains: - ' Antivirus' - ' Firewall' - Application Guard - BitLocker Drive Encryption Service - Encrypting File System - Microsoft Defender - Threat Protection - Windows Event Log - Binary|contains: - 770069006e0064006500660065006e006400 - 4500760065006e0074004c006f006700 - 6d0070007300730076006300 - 530065006e0073006500 - '450046005300' - '420044004500530056004300' condition: all of selection_* falsepositives: - Rare false positives could occur since service termination could happen due to multiple reasons level: high