Query: detection rule: Detects windows utilities loading an unsigned or untrusted DLL. Adversaries often abuse those programs to proxy executio
Matching passage: Sigma rule: Detects windows utilities loading an unsigned or untrusted DLL. Adversaries often abuse those programs to proxy executio. Logsource: windows / image_load. Rule: title: Unsigned DLL Loaded by Windows Utility id: b5de0c9a-6f19-43e0-af4e-55ad01f550af status: test description: 'Detects windows utilities loading an unsigned or untrusted DLL. Adversaries often abuse those programs to proxy execution of malicious code. ' references: - https://www.elastic.co/security-labs/Hunting-for-Suspicious-Windows-Libraries-for-Execution-and-Evasion - https://akhere.hashnode.dev/hunting-unsigned-dlls-using-kql - https://unit42.paloaltonetworks.com/unsigned-dlls/?web_view=true author: Swachchhanda Shrawan Poudel date: 2024-02-28 modified: 2025-10-07 tags: - attack.stealth - attack.t1218.011 - attack.t1218.010 logsource: product: windows category: image_load detection: selection: Image|endswith: - \InstallUtil.exe - \RegAsm.exe - \RegSvcs.exe - \regsvr32.exe - \rundll32.exe filter_main_signed: Signed: 'true' filter_main_sig_status: SignatureStatus: - errorChaining - errorCode_endpoint - errorExpired - trusted - Valid filter_main_signed_null: Signed: null filter_main_signed_empty: Signed: - '' - '-' filter_main_sig_status_null: SignatureStatus: null filter_main_sig_status_empty: SignatureStatus: - '' - '-' filter_main_windows_installer: Image: - C:\Windows\SysWOW64\rundll32.exe - C:\Windows\System32\rundll32.exe ImageLoaded|startswith: C:\Windows\Installer\ ImageLoaded|endswith: - .tmp-\Microsoft.Deployment.WindowsInstaller.dll - .tmp-\Avira.OE.Setup.CustomActions.dll filter_main_assembly: Image|startswith: - C:\Windows\SysWOW64\ - C:\Windows\System32\ - C:\Windows\Microsoft.NET\Framework64 Image|endswith: \RegAsm.exe ImageLoaded|endswith: .dll ImageLoaded|startswith: C:\Windows\assembly\NativeImages filter_optional_klite_codec: Image: - C:\Windows\SysWOW64\regsvr32.exe - C:\Windows\System32\regsvr32.exe ImageLoaded|startswith: - C:\Program Files (x86)\K-Lite Codec Pack\ - C:\Program Files\K-Lite Codec Pack\ condition: selection and not 1 of filter_main_* and not 1 of filter_optional_* falsepositives: - Unknown level: medium
Near-miss passage: Sigma rule: Detects execution of commands via the run dialog box on Windows by checking values of the "RunMRU" registry key. This te. Logsource: windows / registry_set. Rule: title: Potentially Suspicious Command Executed Via Run Dialog Box - Registry id: a7df0e9e-91a5-459a-a003-4cde67c2ff5d related: - id: f9d091f6-f1c7-4873-a24f-050b4a02b4dd type: derived status: test description: 'Detects execution of commands via the run dialog box on Windows by checking values of the "RunMRU" registry key. This technique was seen being abused by threat actors to deceive users into pasting and executing malicious commands, often disguised as CAPTCHA verification steps. ' references: - https://medium.com/@ahmed.moh.farou2/fake-captcha-campaign-on-arabic-pirated-movie-sites-delivers-lumma-stealer-4f203f7adabf - https://medium.com/@shaherzakaria8/downloading-trojan-lumma-infostealer-through-capatcha-1f25255a0e71 - https://www.forensafe.com/blogs/runmrukey.html - https://redcanary.com/blog/threat-intelligence/intelligence-insights-october-2024/ author: Ahmed Farouk, Nasreddine Bencherchali date: 2024-11-01 tags: - attack.execution - attack.t1059.001 logsource: product: windows category: registry_set detection: selection_key: TargetObject|contains: \Microsoft\Windows\CurrentVersion\Explorer\RunMRU selection_powershell_command: Details|contains: - powershell - pwsh selection_powershell_susp_keywords: Details|contains: - ' -e ' - ' -ec ' - ' -en ' - ' -enc ' - ' -enco' - ftp - Hidden - http - iex - Invoke- selection_wmic_command: Details|contains: wmic selection_wmic_susp_keywords: Details|contains: - shadowcopy - process call create condition: selection_key and (all of selection_powershell_* or all of selection_wmic_*) falsepositives: - Unknown level: high