userinit.exe

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

Hashes

Type Hash
MD5 F8DE4D36B6E6F7D7D6666A882312E1D1
SHA1 CF7B6291FC51084DA83F99ED8584926EF34E7D8B
SHA256 FE22DDDDC30C73AA54A7EA96006B14743A864BE9A987FF3B2DEB6B9141C2146A
SHA384 1A68B891DE5946675F41DA5E38A88A2D0C335DF9BC2A87643758EED987F094F9E814A3BE82ED4AF8A6E3D3FB6CD4EA5F
SHA512 9AD7F1E5AD18BECCF3593FA44ABBBE0ED8B66615563BC0147B94F1F6453B106273B1EB2CC15BD52929F0D12D1036F470FB326DAA8A65D91B26A97C5A436853D0
SSDEEP 1536:5gBN/Su36lYqvTmgLPHnL9pCZGr9TNbnJnLyt:yP16lUcHhpTNRLyt
IMP 358B0677DFC8306173782D7EB687E4DF
PESHA1 8AC2D4268081F0C2C2F6295140336C9ACC9CDB24
PE256 DADEBB337B7F6BFFD3A045A5246B94AB0FC551A4516014B8B4E0DA511B83BC80

Runtime Data

Open Handles:

Path Type
(R-D) C:\Windows\System32\en-US\userinit.exe.mui File
(RW-) C:\Windows\System32 File
\BaseNamedObjects\C:*ProgramData*Microsoft*Windows*Caches*{6AF0698E-D558-4F6E-9B3C-3716689AF493}.2.ver0x0000000000000001.db Section
\BaseNamedObjects\C:*ProgramData*Microsoft*Windows*Caches*{DDF571F2-BE98-426D-8288-1A9A39C3FDA2}.2.ver0x0000000000000001.db Section
\BaseNamedObjects\C:*ProgramData*Microsoft*Windows*Caches*cversions.2.ro Section
\Sessions\2\BaseNamedObjects\NLS_CodePage_1252_3_2_0_0 Section
\Sessions\2\BaseNamedObjects\NLS_CodePage_437_3_2_0_0 Section

Loaded Modules:

Path
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\RPCRT4.dll
C:\WINDOWS\System32\sechost.dll
C:\WINDOWS\System32\ucrtbase.dll
C:\WINDOWS\System32\USER32.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: 33000002ED2C45E4C145CF48440000000002ED
  • Thumbprint: 312860D2047EB81F8F58C29FF19ECDB4C634CF6A
  • 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: 10.0.22000.1 (WinBuild.160101.0800)
  • Product Version: 10.0.22000.1
  • Language: English (United States)
  • Legal Copyright: Microsoft Corporation. All rights reserved.
  • Machine Type: 64-bit

File Scan

  • VirusTotal Detections: 0/73
  • VirusTotal Link: https://www.virustotal.com/gui/file/fe22ddddc30c73aa54a7ea96006b14743a864be9a987ff3b2deb6b9141c2146a/detection

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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