--- Name: Syssetup.dll Description: Windows NT System Setup Author: LOLBAS Team Created: 2018-05-25 Commands: - Command: rundll32.exe syssetup.dll,SetupInfObjectInstallAction DefaultInstall 128 c:\test\shady.inf Description: Execute the specified (local or remote) .wsh/.sct script with scrobj.dll in the .inf file by calling an information file directive (section name specified). Usecase: Run local or remote script(let) code through INF file specification (Note May pop an error window). Category: AWL Bypass Privileges: User MitreID: T1218.011 OperatingSystem: Windows 10, Windows 11 Tags: - Input: INF - Command: rundll32 syssetup.dll,SetupInfObjectInstallAction DefaultInstall 128 c:\temp\something.inf Description: Launch an executable file via the SetupInfObjectInstallAction function and .inf file section directive. Usecase: Load an executable payload. Category: Execute Privileges: User MitreID: T1218.011 OperatingSystem: Windows 10, Windows 11 Tags: - Input: INF Full_Path: - Path: c:\windows\system32\syssetup.dll - Path: c:\windows\syswow64\syssetup.dll Code_Sample: - Code: https://raw.githubusercontent.com/huntresslabs/evading-autoruns/master/shady.inf - Code: https://gist.github.com/enigma0x3/469d82d1b7ecaf84f4fb9e6c392d25ba#file-backdoor-minimalist-sct - Code: https://gist.github.com/homjxi0e/87b29da0d4f504cb675bb1140a931415 Detection: - Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/windows/process_creation/proc_creation_win_rundll32_susp_activity.yml - Splunk: https://github.com/splunk/security_content/blob/86a5b644a44240f01274c8b74d19a435c7dae66e/detections/endpoint/detect_rundll32_application_control_bypass___syssetup.yml Resources: - Link: https://twitter.com/pabraeken/status/994392481927258113 - Link: https://twitter.com/harr0ey/status/975350238184697857 - Link: https://twitter.com/bohops/status/975549525938135040 - Link: https://windows10dll.nirsoft.net/syssetup_dll.html Acknowledgement: - Person: Pierre-Alexandre Braeken (Execute) Handle: '@pabraeken' - Person: Matt harr0ey (Execute) Handle: '@harr0ey' - Person: Jimmy (Scriptlet) Handle: '@bohops'