Query: write Sigma for Detects the creation of files with an "LNK" as a second extension. This is sometimes used by malware as a method to abus
Matching passage: Sigma rule: Detects the creation of files with an "LNK" as a second extension. This is sometimes used by malware as a method to abus. Logsource: windows / file_event. Rule: title: Suspicious LNK Double Extension File Created id: 3215aa19-f060-4332-86d5-5602511f3ca8 related: - id: b4926b47-a9d7-434c-b3a0-adc3fa0bd13e type: derived status: test description: 'Detects the creation of files with an "LNK" as a second extension. This is sometimes used by malware as a method to abuse the fact that Windows hides the "LNK" extension by default. ' references: - https://www.crowdstrike.com/blog/meet-crowdstrikes-adversary-of-the-month-for-june-mustang-panda/ - https://www.anomali.com/blog/china-based-apt-mustang-panda-targets-minority-groups-public-and-private-sector-organizations - https://www.cybereason.com/blog/research/a-bazar-of-tricks-following-team9s-development-cycles - https://twitter.com/malwrhunterteam/status/1235135745611960321 - https://twitter.com/luc4m/status/1073181154126254080 author: Nasreddine Bencherchali (Nextron Systems), frack113 date: 2022-11-07 modified: 2023-10-18 tags: - attack.stealth - attack.t1036.007 logsource: category: file_event product: windows detection: selection: TargetFilename|endswith: .lnk TargetFilename|contains: - .doc. - .docx. - .jpg. - .pdf. - .ppt. - .pptx. - .xls. - .xlsx. filter_main_recent: TargetFilename|contains: \AppData\Roaming\Microsoft\Windows\Recent\ filter_optional_office_recent: Image|endswith: - \excel.exe - \powerpnt.exe - \winword.exe TargetFilename|contains: \AppData\Roaming\Microsoft\Office\Recent\ filter_optional_office_excel: Image|endswith: \excel.exe TargetFilename|contains: \AppData\Roaming\Microsoft\Excel filter_optional_office_powerpoint: Image|endswith: \powerpnt.exe TargetFilename|contains: \AppData\Roaming\Microsoft\PowerPoint filter_optional_office_word: Image|endswith: \winword.exe TargetFilename|contains: \AppData\Roaming\Microsoft\Word condition: selection and not 1 of filter_main_* and not 1 of filter_optional_* falsepositives: - Some tuning is required for other general purpose directories of third party apps level: medium regression_tests_path: regression_data/rules/windows/file/file_event/file_event_win_susp_lnk_double_extension/info.yml
Near-miss passage: Sigma rule: Detects potential DLL files being downloaded using the PowerShell Invoke-WebRequest or Invoke-RestMethod cmdlets.. Logsource: windows / process_creation. Rule: title: Potential DLL File Download Via PowerShell Invoke-WebRequest id: 0f0450f3-8b47-441e-a31b-15a91dc243e2 status: test description: Detects potential DLL files being downloaded using the PowerShell Invoke-WebRequest or Invoke-RestMethod cmdlets. references: - https://www.zscaler.com/blogs/security-research/onenote-growing-threat-malware-distribution author: Florian Roth (Nextron Systems), Hieu Tran date: 2023-03-13 modified: 2025-07-18 tags: - attack.command-and-control - attack.execution - attack.t1059.001 - attack.t1105 logsource: product: windows category: process_creation detection: selection: CommandLine|contains: - 'Invoke-RestMethod ' - 'Invoke-WebRequest ' - 'IRM ' - 'IWR ' CommandLine|contains|all: - http - OutFile - .dll condition: selection falsepositives: - Unknown level: medium