diff --git a/rules/windows/image_load/sysmon_wsman_provider_image_load.yml b/rules/windows/image_load/image_load_wsman_provider_image_load.yml similarity index 84% rename from rules/windows/image_load/sysmon_wsman_provider_image_load.yml rename to rules/windows/image_load/image_load_wsman_provider_image_load.yml index ec2373f6f..d9bb86dda 100644 --- a/rules/windows/image_load/sysmon_wsman_provider_image_load.yml +++ b/rules/windows/image_load/image_load_wsman_provider_image_load.yml @@ -3,7 +3,7 @@ id: ad1f4bb9-8dfb-4765-adb6-2a7cfb6c0f94 description: Detects signs of potential use of the WSMAN provider from uncommon processes locally and remote execution. status: experimental date: 2020/06/24 -modified: 2021/11/17 +modified: 2021/11/23 author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research) tags: - attack.execution @@ -30,10 +30,12 @@ detection: - Microsoft.WSMan.Management.dll filter_ps: Image|endswith: '\powershell.exe' + filter_bits: # not available in Sysmon data, but Aurora logs + CommandLine|contains: 'svchost.exe -k netsvcs -p -s BITS' respond_server: Image|endswith: '\svchost.exe' OriginalFileName: 'WsmWmiPl.dll' - condition: (request_client and not filter_ps) or respond_server + condition: (request_client and not filter_ps and not filter_bits) or respond_server falsepositives: - Unknown level: medium diff --git a/rules/windows/image_load/sysmon_uipromptforcreds_dlls.yml b/rules/windows/image_load/sysmon_uipromptforcreds_dlls.yml index 27c50cff0..d43d2cbb0 100644 --- a/rules/windows/image_load/sysmon_uipromptforcreds_dlls.yml +++ b/rules/windows/image_load/sysmon_uipromptforcreds_dlls.yml @@ -3,7 +3,7 @@ id: 9ae01559-cf7e-4f8e-8e14-4c290a1b4784 description: Detects potential use of UIPromptForCredentials functions by looking for some of the DLLs needed for it. status: experimental date: 2020/10/20 -modified: 2021/11/20 +modified: 2021/11/23 author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research) tags: - attack.credential_access @@ -28,6 +28,7 @@ detection: Image|startswith: - 'C:\Windows\System32\' - 'C:\Windows\explorer.exe' + - 'C:\Program Files\' condition: selection and not filter falsepositives: - other legitimate processes loading those DLLs in your environment. diff --git a/rules/windows/process_creation/win_susp_psexex_paexec_escalate_system.yml b/rules/windows/process_creation/win_susp_psexex_paexec_escalate_system.yml new file mode 100644 index 000000000..1d194067c --- /dev/null +++ b/rules/windows/process_creation/win_susp_psexex_paexec_escalate_system.yml @@ -0,0 +1,29 @@ +title: PsExec/PAExec Escalation to LOCAL SYSTEM +id: 8834e2f7-6b4b-4f09-8906-d2276470ee23 +status: experimental +description: Detects suspicious flags used by PsExec and PAExec to escalate a command line to LOCAL_SYSTEM rights +references: + - https://docs.microsoft.com/en-us/sysinternals/downloads/psexec + - https://www.poweradmin.com/paexec/ + - https://www.fireeye.com/blog/threat-research/2020/10/kegtap-and-singlemalt-with-a-ransomware-chaser.html +author: Florian Roth +date: 2021/11/23 +logsource: + category: process_creation + product: windows +detection: + selection_cmd_to_system: # Escalation to LOCAL_SYSTEM + CommandLine|endswith: ' -s cmd.exe' + selection_supporting_flags: + CommandLine|contains: + - 'PsExec' + - 'PAExec' + - 'accepteula' + - 'cmd /c ' + condition: selection_supporting_flags and selection_cmd_to_system +falsepositives: + - Admins that use PsExec or PAExec to escalate to the SYSTEM account for maintenance purposes (rare) +level: high +tags: + - attack.develop_capabilities + - attack.t1587.001 \ No newline at end of file diff --git a/rules/windows/process_creation/win_susp_psexex_paexec_flags.yml b/rules/windows/process_creation/win_susp_psexex_paexec_flags.yml index 51926aa0f..972ce610d 100644 --- a/rules/windows/process_creation/win_susp_psexex_paexec_flags.yml +++ b/rules/windows/process_creation/win_susp_psexex_paexec_flags.yml @@ -8,21 +8,21 @@ references: - https://www.fireeye.com/blog/threat-research/2020/10/kegtap-and-singlemalt-with-a-ransomware-chaser.html author: Florian Roth date: 2021/05/22 +modified: 2021/11/23 logsource: category: process_creation product: windows detection: selection_flags_1: # Escalation to LOCAL_SYSTEM - CommandLine|contains|all: - - '\\127.0.0.1' - - ' -s ' - - 'cmd.exe' + CommandLine|endswith: + - ' -s cmd.exe' + - ' -s -i cmd.exe' selection_flags_2: CommandLine|contains|all: # Accepting EULA in commandline - often used in automated attacks - - ' /accepteula ' - - 'cmd /c ' + - 'accepteula' - ' -u ' - ' -p ' + - ' \\' filter: CommandLine|contains: - 'paexec'