title: Winlogon Helper DLL id: 851c506b-6b7c-4ce2-8802-c703009d03c0 status: experimental description: Winlogon.exe is a Windows component responsible for actions at logon/logoff as well as the secure attention sequence (SAS) triggered by Ctrl-Alt-Delete. Registry entries in HKLM\Software[Wow6432Node]Microsoft\Windows NT\CurrentVersion\Winlogon\ and HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ are used to manage additional helper programs and functionalities that support Winlogon. Malicious modifications to these Registry keys may cause Winlogon to load and execute malicious DLLs and/or executables. author: Timur Zinniatullin, oscd.community date: 2019/10/21 modified: 2019/11/04 references: - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1004/T1004.yaml logsource: product: windows service: powershell description: 'Script block logging must be enabled' detection: selection: EventID: 4104 keyword1: - '*Set-ItemProperty*' - '*New-Item*' keyword2: - '*CurrentVersion\Winlogon*' condition: selection and ( keyword1 and keyword2 ) falsepositives: - Unknown level: medium tags: - attack.persistence - attack.t1004