diff --git a/rules/windows/image_load/sysmon_alternate_powershell_hosts_moduleload.yml b/rules/windows/image_load/sysmon_alternate_powershell_hosts_moduleload.yml index 360d7c36d..396ed5fad 100644 --- a/rules/windows/image_load/sysmon_alternate_powershell_hosts_moduleload.yml +++ b/rules/windows/image_load/sysmon_alternate_powershell_hosts_moduleload.yml @@ -3,13 +3,13 @@ id: fe6e002f-f244-4278-9263-20e4b593827f description: Detects alternate PowerShell hosts potentially bypassing detections looking for powershell.exe status: experimental date: 2019/09/12 -modified: 2021/12/03 +modified: 2021/12/04 author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research) tags: - attack.execution - attack.t1059.001 references: - - https://threathunterplaybook.com/notebooks/windows/02_execution/WIN-190815181010.html + - https://threathunterplaybook.com/notebooks/windows/02_execution/WIN-190610201010.html logsource: product: windows category: image_load @@ -18,9 +18,12 @@ detection: Description: 'System.Management.Automation' ImageLoaded|contains: 'System.Management.Automation' filter: - Image|endswith: + - Image|endswith: - '\powershell.exe' - '\mscorsvw.exe' + - Image|startswith: + - 'C:\Program Files (x86)\Microsoft Visual Studio\' + - 'C:\Program Files\Microsoft Visual Studio\' condition: selection and not filter falsepositives: - Unknown diff --git a/rules/windows/image_load/sysmon_susp_system_drawing_load.yml b/rules/windows/image_load/sysmon_susp_system_drawing_load.yml index e4b181dcb..8dd350f87 100644 --- a/rules/windows/image_load/sysmon_susp_system_drawing_load.yml +++ b/rules/windows/image_load/sysmon_susp_system_drawing_load.yml @@ -3,7 +3,7 @@ id: 666ecfc7-229d-42b8-821e-1a8f8cb7057c description: A General detection for processes loading System.Drawing.ni.dll. This could be an indicator of potential Screen Capture. status: experimental date: 2020/05/02 -modified: 2021/12/03 +modified: 2021/12/04 author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research) tags: - attack.collection @@ -18,13 +18,8 @@ detection: selection: ImageLoaded|endswith: '\System.Drawing.ni.dll' filter: - Image|endswith: - - '\WmiPrvSE.exe' - - '\mmc.exe' - - '\Services\Microsoft.VisualStudio.Setup.Service\BackgroundDownload.exe' - - '\mscorsvw.exe' - - '\ServiceHub.Host.CLR.x86.exe' - - '\ServiceHub.ThreadedWaitDialog.exe' + # The number of false positives was too high - we had to do this broader filter + # based on the following paths that shouldn't be writable to an unprivileged user Image|startswith: - 'C:\Program Files\' - 'C:\Program Files (x86)\'