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Fixes & Updates#4577

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nasbench merged 45 commits intoSigmaHQ:masterfrom
nasbench:fix-env-stuff
Dec 21, 2023
Merged

Fixes & Updates#4577
nasbench merged 45 commits intoSigmaHQ:masterfrom
nasbench:fix-env-stuff

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@nasbench nasbench commented Nov 17, 2023

Summary of the Pull Request

This PR updates and fixes multiple rules

Changelog

fix: Access To Windows Credential History File By Uncommon Application - Enhance FP filters
fix: Access To Windows DPAPI Master Keys By Uncommon Application - Enhance FP filters
fix: Amsi.DLL Load By Uncommon Process - Moved to threat hunting folder and update false positive filters to remove hardcoded C:
fix: Bad Opsec Defaults Sacrificial Processes With Improper Arguments - Typo in condition
fix: Credential Manager Access By Uncommon Application - Enhance FP filters
fix: Elevated System Shell Spawned From Uncommon Parent Location - Enhance FP filters
fix: Execution of Suspicious File Type Extension - Add new extensions to reduce FP
fix: Important Windows Eventlog Cleared - Update selection to remove "Application" log as it was generating a lot of FP in some environments
fix: Malicious PowerShell Commandlets - ScriptBlock - Remove some part of the selection due to FP matches as they were generic cmdlet names
fix: Potential Direct Syscall of NtOpenProcess - Add "Adobe" filter
fix: Potential Shim Database Persistence via Sdbinst.EXE - Update FP filter for "iisexpressshim" sdb
fix: Potentially Suspicious AccessMask Requested From LSASS - Add new FP filter for "procmon" process
fix: PowerView PowerShell Cmdlets - ScriptBlock - Remove some part of the selection due to FP matches as they were generic cmdlet names
fix: PSScriptPolicyTest Creation By Uncommon Process - Add new filter for "sdiagnhost"
fix: Relevant Anti-Virus Signature Keywords In Application Log - Update false positive filters
fix: Remote Access Tool Services Have Been Installed - Security - Fix typo in field name
fix: Suspicious File Creation Activity From Fake Recycle.Bin Folder - Remove RECYCLE.BIN\ as it was added as a typo and is a legitimate location.
fix: Uncommon Child Process Of Conhost.EXE - Add new FP filters
fix: Uncommon File Created In Office Startup Folder - Add new extension to filter out FP generated with MS Access databases
fix: Uncommon PowerShell Hosts - Moved to threat hunting folder and updated false positive filter list
fix: Use Of Remove-Item to Delete File - ScriptBlock - Moved to threat hunting folder and Update logic to be more accurate
fix: User with Privileges Logon - Move to placeholder rules and update the FP filter to account for different workstations
fix: Windows Event Auditing Disabled - Enhance list of false positive filters with additional GUID
fix: WMI Module Loaded By Uncommon Process - Moved to threat hunting folder and update and restructure false positive filters
new: Communication To Uncommon Destination Ports
new: Potentially Suspicious Execution Of Regasm/Regsvcs With Uncommon Extension
remove: Credential Dumping Tools Service Execution
remove: New Service Uses Double Ampersand in Path
remove: Powershell File and Directory Discovery
remove: PowerShell Scripts Run by a Services
remove: Security Event Log Cleared
remove: Suspicious Get-WmiObject
remove: Windows Defender Threat Detection Disabled
update: Access To Browser Credential Files By Uncommon Application - Increase level to medium and enhance filters and selections
update: Add Potential Suspicious New Download Source To Winget - Reduce level to medium
update: ADFS Database Named Pipe Connection By Uncommon Tool - Enhance coverage by improving paths selection
update: CodeIntegrity - Unmet Signing Level Requirements By File Under Validation - Reduce level to low
update: Copy From Or To Admin Share Or Sysvol Folder - Enhance selection to be more accurate
update: Eventlog Cleared - Update FP filter to remove "Application" log and increase coverage
update: Failed Code Integrity Checks - Reduce level to informational
update: HH.EXE Execution - Reduce level to low
update: Locked Workstation - Reduce level to informational
update: Malicious Driver Load By Name - Increase coverage based on LOLDrivers data
update: Meterpreter or Cobalt Strike Getsystem Service Installation - Security - Reduce level to high and restructure selections
update: Meterpreter or Cobalt Strike Getsystem Service Installation - System - Reduce level to high and restructure selections
update: Potential Credential Dumping Activity Via LSASS - Reduce level to medium and comment out noisy access masks
update: Potential PowerShell Execution Policy Tampering - Remove "RemoteSigned" as it doesn't fit with the current logic
update: Potentially Suspicious Execution Of Regasm/Regsvcs From Uncommon Location - Reduce level to medium and update logic
update: Potentially Suspicious Malware Callback Communication - Increase coverage by adding new additional ports
update: PUA - Nmap/Zenmap Execution - Reduce level to medium
update: PUA - Process Hacker Execution - Reduce level to medium
update: PUA - Radmin Viewer Utility Execution - Reduce level to medium
update: Rundll32 Execution With Uncommon DLL Extension - Enhance DLL extension list
update: SASS Access From Non System Account - Reduce level to medium and enhance false positive filters
update: Suspicious Executable File Creation - Enhance coverage by removing hardocded "C:"
update: Suspicious Program Location with Network Connections - Increase accuracy by enhancing the selection to focus on the start of the folder and partition
update: Suspicious Schtasks From Env Var Folder - Reduce level to medium
update: Suspicious Shim Database Patching Activity - Add new processes to increase coverage
update: Uncommon Extension Shim Database Installation Via Sdbinst.EXE - Reduce level to medium
update: Whoami Utility Execution - Reduce level to low
update: Whoami.EXE Execution With Output Option - Reduce level to medium
update: Windows Defender Malware Detection History Deletion - Reduce level to informational
update: WMI Event Consumer Created Named Pipe - Reduce leve to medium

Example Log Event

N/A

Fixed Issues

Fixes #4572 (Thanks @Blackmore-Robert)
Fixes #4584 (Thanks @swachchhanda000)
Fixed #4587 (Thanks @celalettin-turgut)
Fixed #4613 (Thanks @AaronS97)

SigmaHQ Rule Creation Conventions

  • If your PR adds new rules, please consider following and applying these conventions

@github-actions github-actions Bot added Rules Windows Pull request add/update windows related rules labels Nov 17, 2023
@nasbench nasbench self-assigned this Nov 22, 2023
@nasbench nasbench linked an issue Nov 22, 2023 that may be closed by this pull request
@nasbench nasbench marked this pull request as ready for review December 18, 2023 11:43
@nasbench nasbench requested a review from phantinuss December 18, 2023 11:43
@nasbench nasbench added 2nd Review Needed and removed Work In Progress Some changes are needed labels Dec 18, 2023
Comment thread rules-placeholder/windows/builtin/security/win_security_admin_logon.yml Outdated
Comment thread rules/windows/process_creation/proc_creation_win_susp_non_exe_image.yml Outdated
Comment thread rules/windows/process_creation/proc_creation_win_whoami_all_execution.yml Outdated
Comment thread rules/windows/process_creation/proc_creation_win_whoami_priv_discovery.yml Outdated
phantinuss and others added 13 commits December 19, 2023 12:38
…logon.yml

Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
…h_pc_alternate_powershell_hosts.yml

Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
…_ps_remove_item_path.yml

Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
…re_callback_ports_uncommon.yml

Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
…mmon_dll_extension.yml

Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
…_system_shell_uncommon_parent.yml

Co-authored-by: phantinuss <79651203+phantinuss@users.noreply.github.com>
@nasbench nasbench merged commit e052677 into SigmaHQ:master Dec 21, 2023
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