userinit.exe

  • File Path: C:\Windows\system32\userinit.exe
  • Description: Userinit Logon Application

Hashes

Type Hash
MD5 BF8825D08BC235F0609CA8BBEF4E179C
SHA1 470C3E60F9B2B6D83F95C7916A5361E34DEC3471
SHA256 1FE7F7C59EC7EAA276739FA85F7DDA6136D81184E0AEB385B6AC9FEAAA8C4394
SHA384 2F6C88E35212D628149451D95FE10F37B8ECDDADA4CA9216451573415C9DF440A3C1FF432C6E4EE5D12161BC87808BA6
SHA512 0D54F15CDD2245A540B588566C3F5FE70E1401AABE08C2052C72CB7A8E10741A37817816C29E41FD50F9BE57D01AA0DAC911120E7CBB44E9DBD6B07D3BD6E70C
SSDEEP 384:UPn1lWx3jWG/eBjZH7ehyFQQ65SEvhmaB9YQTpkEBVSC+lfPIeb51MQneA6pgWxk:UPnyWG/e1Zbo/rSiPTpr+Rh5XnhMa
IMP 8419D97ABDFEB6C320F0C39028647572
PESHA1 DF688108336B5E2AC79D652521CAE6F14BC4D450
PE256 A5160EF5F4B97E938DA7E956A3331FB66EA3F9EA7E7D8BEEF313F318F2C11B98

Runtime Data

Open Handles:

Path Type
(R-D) C:\Windows\System32\en-US\userinit.exe.mui File
(RW-) C:\Users\user File
\BaseNamedObjects\C:*ProgramData*Microsoft*Windows*Caches*{6AF0698E-D558-4F6E-9B3C-3716689AF493}.2.ver0x0000000000000004.db Section
\BaseNamedObjects\C:*ProgramData*Microsoft*Windows*Caches*{DDF571F2-BE98-426D-8288-1A9A39C3FDA2}.2.ver0x0000000000000004.db Section
\BaseNamedObjects\C:*ProgramData*Microsoft*Windows*Caches*cversions.2.ro Section
\BaseNamedObjects\NLS_CodePage_1252_3_2_0_0 Section
\BaseNamedObjects\NLS_CodePage_437_3_2_0_0 Section

Loaded Modules:

Path
C:\Windows\System32\bcryptPrimitives.dll
C:\Windows\System32\combase.dll
C:\Windows\System32\GDI32.dll
C:\Windows\System32\gdi32full.dll
C:\Windows\System32\IMM32.DLL
C:\Windows\System32\KERNEL32.DLL
C:\Windows\System32\KERNELBASE.dll
C:\Windows\System32\msvcp_win.dll
C:\Windows\System32\msvcrt.dll
C:\Windows\SYSTEM32\ntdll.dll
C:\Windows\System32\profapi.dll
C:\Windows\System32\RPCRT4.dll
C:\Windows\System32\sechost.dll
C:\Windows\System32\ucrtbase.dll
C:\Windows\System32\USER32.dll
C:\Windows\system32\USERENV.dll
C:\Windows\system32\userinit.exe
C:\Windows\SYSTEM32\userinitext.dll
C:\Windows\system32\uxtheme.dll
C:\Windows\System32\win32u.dll
C:\Windows\SYSTEM32\winsta.dll

Signature

  • Status: Signature verified.
  • Serial: 33000001C422B2F79B793DACB20000000001C4
  • Thumbprint: AE9C1AE54763822EEC42474983D8B635116C8452
  • Issuer: CN=Microsoft Windows Production PCA 2011, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
  • Subject: CN=Microsoft Windows, O=Microsoft Corporation, L=Redmond, S=Washington, C=US

File Metadata

  • Original Filename: USERINIT.EXE.MUI
  • Product Name: Microsoft Windows Operating System
  • Company Name: Microsoft Corporation
  • File Version: 10.0.17763.1 (WinBuild.160101.0800)
  • Product Version: 10.0.17763.1
  • Language: English (United States)
  • Legal Copyright: Microsoft Corporation. All rights reserved.
  • Machine Type: 64-bit

File Scan

  • VirusTotal Detections: 0/68
  • VirusTotal Link: https://www.virustotal.com/gui/file/1fe7f7c59ec7eaa276739fa85f7dda6136d81184e0aeb385b6ac9feaaa8c4394/detection/

File Similarity (ssdeep match)

File Score
C:\WINDOWS\system32\userinit.exe 71

Possible Misuse

The following table contains possible examples of userinit.exe being misused. While userinit.exe is not inherently malicious, its legitimate functionality can be abused for malicious purposes.

Source Source File Example License
sigma sysmon_suspicious_remote_thread.yml - '\userinit.exe' DRL 1.0
sigma proc_creation_win_logon_scripts_userinitmprlogonscript_proc.yml ParentImage\|endswith: '\userinit.exe' DRL 1.0
sigma proc_creation_win_susp_direct_asep_reg_keys_modification.yml - '\software\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit' DRL 1.0
sigma proc_creation_win_susp_userinit_child.yml title: Suspicious Userinit Child Process DRL 1.0
sigma proc_creation_win_susp_userinit_child.yml description: Detects a suspicious child process of userinit DRL 1.0
sigma proc_creation_win_susp_userinit_child.yml ParentImage\|endswith: '\userinit.exe' DRL 1.0
sigma registry_event_asep_reg_keys_modification.yml - '\Winlogon\Userinit' DRL 1.0
sigma registry_event_asep_reg_keys_modification_currentversion_nt.yml - '\Winlogon\Userinit' DRL 1.0
malware-ioc misp_invisimole.json "description": "Adding an entry to the \"run keys\" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. (Citation: Microsoft Run Key) These programs will be executed under the context of the user and will have the account's associated permissions level.\n\nThe following run keys are created by default on Windows systems:\n* <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Run</code>\n* <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\RunOnce</code>\n* <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\Run</code>\n* <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\RunOnce</code>\n\nThe <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\RunOnceEx</code> is also available but is not created by default on Windows Vista and newer. Registry run key entries can reference programs directly or list them as a dependency. (Citation: Microsoft RunOnceEx APR 2018) For example, it is possible to load a DLL at logon using a \"Depend\" key with RunOnceEx: <code>reg add HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\RunOnceEx\\0001\\Depend /v 1 /d \"C:\\temp\\evil[.]dll\"</code> (Citation: Oddvar Moe RunOnceEx Mar 2018)\n\nThe following Registry keys can be used to set startup folder items for persistence:\n* <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders</code>\n* <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders</code>\n* <code>HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders</code>\n* <code>HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders</code>\n\nThe following Registry keys can control automatic startup of services during boot:\n* <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\RunServicesOnce</code>\n* <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\RunServicesOnce</code>\n* <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\RunServices</code>\n* <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\RunServices</code>\n\nUsing policy settings to specify startup programs creates corresponding values in either of two Registry keys:\n* <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\Run</code>\n* <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\Run</code>\n\nThe Winlogon key controls actions that occur when a user logs on to a computer running Windows 7. Most of these actions are under the control of the operating system, but you can also add custom actions here. The <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\Userinit</code> and <code>HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\Shell</code> subkeys can automatically launch programs.\n\nPrograms listed in the load value of the registry key <code>HKEY_CURRENT_USER\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Windows</code> run when any user logs on.\n\nBy default, the multistring BootExecute value of the registry key <code>HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\Control\\Session Manager</code> is set to autocheck autochk *. This value causes Windows, at startup, to check the file-system integrity of the hard disks if the system has been shut down abnormally. Adversaries can add other programs or processes to this registry value which will automatically launch at boot.\n\n\nAdversaries can use these configuration locations to execute malware, such as remote access tools, to maintain persistence through system reboots. Adversaries may also use [Masquerading](https://attack.mitre.org/techniques/T1036) to make the Registry entries look as if they are associated with legitimate programs.", © ESET 2014-2018
malware-ioc part3.adoc userinit.exe © ESET 2014-2018
atomic-red-team index.md - Atomic Test #2: Winlogon Userinit Key Persistence - PowerShell [windows] MIT License. © 2018 Red Canary
atomic-red-team windows-index.md - Atomic Test #2: Winlogon Userinit Key Persistence - PowerShell [windows] MIT License. © 2018 Red Canary
atomic-red-team T1012.md reg query “HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit” MIT License. © 2018 Red Canary
atomic-red-team T1547.001.md The Winlogon key controls actions that occur when a user logs on to a computer running Windows 7. Most of these actions are under the control of the operating system, but you can also add custom actions here. The HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit and HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell subkeys can automatically launch programs. MIT License. © 2018 Red Canary
atomic-red-team T1547.004.md * Winlogon\Userinit - points to userinit.exe, the user initialization program executed when a user logs on MIT License. © 2018 Red Canary
atomic-red-team T1547.004.md - Atomic Test #2 - Winlogon Userinit Key Persistence - PowerShell MIT License. © 2018 Red Canary
atomic-red-team T1547.004.md ## Atomic Test #2 - Winlogon Userinit Key Persistence - PowerShell MIT License. © 2018 Red Canary
atomic-red-team T1547.004.md PowerShell code to set Winlogon userinit key to execute a binary at logon along with userinit.exe. MIT License. © 2018 Red Canary
atomic-red-team T1547.004.md Set-ItemProperty “HKCU:\Software\Microsoft\Windows NT\CurrentVersion\Winlogon" “Userinit” “Userinit.exe, #{binary_to_execute}” -Force MIT License. © 2018 Red Canary
atomic-red-team T1547.004.md Remove-ItemProperty -Path “HKCU:\Software\Microsoft\Windows NT\CurrentVersion\Winlogon" -Name “Userinit” -Force -ErrorAction Ignore MIT License. © 2018 Red Canary

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