title: Potential Defense Evasion Via Rename Of Highly Relevant Binaries id: 0ba1da6d-b6ce-4366-828c-18826c9de23e related: - id: 36480ae1-a1cb-4eaa-a0d6-29801d7e9142 type: similar - id: 2569ed8c-1147-498a-9b8c-2ad3656b10ed # Renamed Rundll32 Specific type: derived - id: a7a7e0e5-1d57-49df-9c58-9fe5bc0346a2 # Renamed PsExec type: obsolete - id: d178a2d7-129a-4ba4-8ee6-d6e1fecd5d20 # Renamed PowerShell type: obsolete - id: d4d2574f-ac17-4d9e-b986-aeeae0dc8fe2 # Renamed Rundll32 type: obsolete status: test description: Detects the execution of a renamed binary often used by attackers or malware leveraging new Sysmon OriginalFileName datapoint. references: - https://mgreen27.github.io/posts/2019/05/12/BinaryRename.html - https://mgreen27.github.io/posts/2019/05/29/BinaryRename2.html - https://www.trendmicro.com/vinfo/hk-en/security/news/cybercrime-and-digital-threats/megacortex-ransomware-spotted-attacking-enterprise-networks - https://twitter.com/christophetd/status/1164506034720952320 - https://threatresearch.ext.hp.com/svcready-a-new-loader-reveals-itself/ - https://www.huntress.com/blog/malicious-browser-extention-crashfix-kongtuke author: Matthew Green - @mgreen27, Florian Roth (Nextron Systems), frack113 date: 2019-06-15 modified: 2026-06-29 tags: - attack.stealth - attack.t1036.003 - car.2013-05-009 logsource: category: process_creation product: windows detection: selection: - Description: 'Execute processes remotely' - Product: 'Sysinternals PsExec' - Description|startswith: - 'Windows PowerShell' - 'pwsh' - OriginalFileName: - 'certutil.exe' - 'cmstp.exe' - 'cscript.exe' - 'IE4UINIT.EXE' - 'finger.exe' - 'mshta.exe' - 'msiexec.exe' - 'msxsl.exe' - 'powershell_ise.exe' - 'powershell.exe' - 'psexec.c' # old versions of psexec (2016 seen) - 'psexec.exe' - 'psexesvc.exe' - 'pwsh.dll' - 'reg.exe' - 'regsvr32.exe' - 'rundll32.exe' - 'WerMgr' - 'wmic.exe' - 'wscript.exe' filter: Image|endswith: - '\certutil.exe' - '\cmstp.exe' - '\cscript.exe' - '\ie4uinit.exe' - '\finger.exe' - '\mshta.exe' - '\msiexec.exe' - '\msxsl.exe' - '\powershell_ise.exe' - '\powershell.exe' - '\psexec.exe' - '\psexec64.exe' - '\psexec64a.exe' - '\PSEXESVC.exe' - '\pwsh.exe' - '\reg.exe' - '\regsvr32.exe' - '\rundll32.exe' - '\wermgr.exe' - '\wmic.exe' - '\wscript.exe' condition: selection and not filter falsepositives: - Custom applications use renamed binaries adding slight change to binary name. Typically this is easy to spot and add to whitelist - PsExec installed via Windows Store doesn't contain original filename field (False negative) level: high regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_renamed_binary_highly_relevant/info.yml