Query: alert when Detects a suspicious call to the user32.dll function that locks the user workstation
Matching passage: Sigma rule: Detects a suspicious call to the user32.dll function that locks the user workstation. Logsource: windows / process_creation. Rule: title: Suspicious Workstation Locking via Rundll32 id: 3b5b0213-0460-4e3f-8937-3abf98ff7dcc status: test description: Detects a suspicious call to the user32.dll function that locks the user workstation references: - https://app.any.run/tasks/2aef9c63-f944-4763-b3ef-81eee209d128/ author: frack113 date: 2022-06-04 modified: 2023-02-09 tags: - attack.stealth logsource: category: process_creation product: windows detection: selection_call_img: - Image|endswith: \rundll32.exe - OriginalFileName: RUNDLL32.EXE selection_call_parent: ParentImage|endswith: \cmd.exe selection_call_cli: CommandLine|contains: user32.dll, selection_function: CommandLine|contains: LockWorkStation condition: all of selection_* falsepositives: - Scripts or links on the user desktop used to lock the workstation instead of Windows+L or the menu option level: medium
Near-miss passage: Sigma rule: Detects a suspicious copy operation that tries to copy a program from system (System32, SysWOW64, WinSxS) directories to. Logsource: windows / process_creation. Rule: title: Suspicious Copy From or To System Directory id: fff9d2b7-e11c-4a69-93d3-40ef66189767 related: - id: 855bc8b5-2ae8-402e-a9ed-b889e6df1900 type: derived status: test description: 'Detects a suspicious copy operation that tries to copy a program from system (System32, SysWOW64, WinSxS) directories to another on disk. Often used to move LOLBINs such as ''certutil'' or ''desktopimgdownldr'' to a different location with a different name in order to bypass detections based on locations. ' references: - https://www.hybrid-analysis.com/sample/8da5b75b6380a41eee3a399c43dfe0d99eeefaa1fd21027a07b1ecaa4cd96fdd?environmentId=120 - https://web.archive.org/web/20180331144337/https://www.fireeye.com/blog/threat-research/2018/03/sanny-malware-delivery-method-updated-in-recently-observed-attacks.html - https://thedfirreport.com/2023/08/28/html-smuggling-leads-to-domain-wide-ransomware/ author: Florian Roth (Nextron Systems), Markus Neis, Tim Shelton (HAWK.IO), Nasreddine Bencherchali (Nextron Systems) date: 2020-07-03 modified: 2026-03-16 tags: - attack.stealth - attack.t1036.003 logsource: category: process_creation product: windows detection: selection_img_cmd: Image|endswith: \cmd.exe CommandLine|contains: 'copy ' selection_img_pwsh: Image|endswith: - \powershell.exe - \pwsh.exe CommandLine|contains: - copy-item - ' copy ' - 'cpi ' - ' cp ' selection_img_other: - Image|endswith: - \robocopy.exe - \xcopy.exe - OriginalFileName: - robocopy.exe - XCOPY.EXE selection_target: CommandLine|re|i: \s['"]?C:\\Windows\\(?:System32|SysWOW64|WinSxS) filter_optional_avira: Image|endswith: \cmd.exe CommandLine|contains|all: - /c copy - \Temp\ - \avira_system_speedup.exe CommandLine|contains: - C:\Program Files\Avira\ - C:\Program Files (x86)\Avira\ condition: 1 of selection_img_* and selection_target and not 1 of filter_optional_* falsepositives: - Depend on scripts and administrative tools used in the monitored environment (For example an admin scripts like https://www.itexperience.net/sccm-batch-files-and-32-bits-processes-on-64-bits-os/) - When cmd.exe and xcopy.exe are called directly - When the command contains the keywords but not in the correct order level: medium