Query: Sigma YAML for windows / process_creation
Matching passage: Sigma rule: Detects file association changes using the builtin "assoc" command. When a file is opened, the default program used to o. Logsource: windows / process_creation. Rule: title: Change Default File Association Via Assoc id: 3d3aa6cd-6272-44d6-8afc-7e88dfef7061 related: - id: ae6f14e6-14de-45b0-9f44-c0986f50dc89 type: similar status: test description: 'Detects file association changes using the builtin "assoc" command. When a file is opened, the default program used to open the file (also called the file association or handler) is checked. File association selections are stored in the Windows Registry and can be edited by users, administrators, or programs that have Registry access or by administrators using the built-in assoc utility. Applications can modify the file association for a given file extension to call an arbitrary program when a file with the given extension is opened. ' references: - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.001/T1546.001.md author: Timur Zinniatullin, oscd.community date: 2019-10-21 modified: 2023-03-06 tags: - attack.privilege-escalation - attack.persistence - attack.t1546.001 logsource: category: process_creation product: windows detection: selection_img: - Image|endswith: \cmd.exe - OriginalFileName: Cmd.Exe selection_cli: CommandLine|contains: assoc condition: all of selection_* falsepositives: - Admin activity level: low regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_cmd_assoc_execution/info.yml
Near-miss passage: Sigma rule: Detects usage of known powershell cmdlets such as "Clear-EventLog" to clear the Windows event logs. Logsource: windows / ps_script. Rule: title: Suspicious Eventlog Clear id: 0f017df3-8f5a-414f-ad6b-24aff1128278 related: - id: cc36992a-4671-4f21-a91d-6c2b72a2edf5 type: derived status: test description: Detects usage of known powershell cmdlets such as "Clear-EventLog" to clear the Windows event logs references: - https://twitter.com/oroneequalsone/status/1568432028361830402 - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.001/T1070.001.md - https://eqllib.readthedocs.io/en/latest/analytics/5b223758-07d6-4100-9e11-238cfdd0fe97.html - https://stackoverflow.com/questions/66011412/how-to-clear-a-event-log-in-powershell-7 - https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.eventing.reader.eventlogsession.clearlog?view=windowsdesktop-9.0&viewFallbackFrom=dotnet-plat-ext-5.0#System_Diagnostics_Eventing_Reader_EventLogSession_ClearLog_System_String_ - https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.eventlog.clear author: Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems) date: 2022-09-12 modified: 2025-10-06 tags: - attack.defense-impairment - attack.t1685.005 logsource: product: windows category: ps_script definition: 'Requirements: Script Block Logging must be enabled' detection: selection: - ScriptBlockText|contains: - 'Clear-EventLog ' - 'Remove-EventLog ' - 'Limit-EventLog ' - 'Clear-WinEvent ' - ScriptBlockText|contains|all: - Eventing.Reader.EventLogSession - ClearLog - ScriptBlockText|contains|all: - Diagnostics.EventLog - Clear condition: selection falsepositives: - Rare need to clear logs before doing something. Sometimes used by installers or cleaner scripts. The script should be investigated to determine if it's legitimate level: medium