runas.exe

What is runas.exe?

runas.exe is the Windows utility that launches a program under alternate credentials. It prompts for a separate user account and runs the target executable with those privileges. It is part of the Windows operating system and used for administrative tasks.

It implements the RunAs API; when invoked it creates a new process with credentials, authenticates against the local or domain account, and then executes the specified target under that context.

Types of RunAs Operations

• Direct RunAs: Manual elevated launch via RunAs dialog
• Scripted RunAs: Automated script or task scheduler invoking runas.exe
• Credential Cache: Temporary credentials in memory for a task
• Shell Integration: Windows shell may offer Run as administrator context
• Remote Execution: Running a process on another account over a remote session

Is runas.exe Safe?

Yes, runas.exe is safe when it is the legitimate Microsoft binary located in C:\Windows\System32 and signed by Microsoft.

Is runas.exe a Virus or Malware?

The real runas.exe is not a virus. Malware may masquerade with similar names. Always verify location and digital signature.

How to Tell if runas.exe is Legitimate or Malware

1. File Location: Must be in C:\Windows\System32\runas.exe or C:\Windows\SysWOW64\runas.exe. Other locations are suspicious.
2. Digital Signature: Right-click file in Explorer -> Properties -> Digital Signatures. Should show "Microsoft Corporation".
3. Certificate Authority: Check certificate chain to Microsoft Code Signing (Microsoft Code Signing PCA) else suspicious.
4. Behavior: Unsolicited prompts or automatic launches without user action are suspicious.

Why Is runas.exe Running on My PC?

runas.exe runs when you explicitly launch a program with alternate credentials or when a script, task, or admin tool requests it. It does not normally run continuously.

Reasons it's running:

• Manual Elevation Requests: You initiated RunAs to run a program with different credentials, prompting for a password.
• Scripted or Scheduled Tasks: Automation may invoke runas.exe to launch tasks under another account.
• Administrative Maintenance: IT tools or installers use runas.exe to perform elevated actions during setup.
• Credential Guard and UAC: User Account Control prompts and credential guard workflows may trigger RunAs for security checks.
• Remote or Hybrid Sessions: Administrative sessions or remote admin consoles might spawn runas.exe for remote tasks.

Can I Disable or Remove runas.exe?

Disabling runas.exe is not generally recommended because some admin tools rely on it. You can limit its use via policies, UAC, or avoid invoking RunAs.

How to Stop Unwanted RunAs Prompts

• Review Scheduled Tasks: Open Task Scheduler and check tasks invoking RunAs; disable if unnecessary.
• Check Startup Items: Ensure RunAs is not invoked by startup scripts or login tasks.
• Group Policy: Modify policies to restrict credentials or disallow RunAs usage for non-admins.
• Application Settings: In admin tools, configure to use elevated prompts only when required.
• Security Software: Ensure antivirus or EDR does not falsely block or auto-run runas.exe.

How to Remove runas.exe

• ✔ Do not attempt to delete from System32; it is a Windows component. Use Windows Features or policy changes to reduce usage instead.
• ✔ If a separate third-party utility ships runas.exe, uninstall that specific tool via Apps & Features.

Common Problems: RunAs Prompts, Failures, or Misuse

If runas.exe misbehaves or prompts unexpectedly, consider these scenarios and fixes.

Common Causes & Solutions

• Unexpected RunAs prompts: Identify the application requesting elevated rights and ensure legitimate admin usage; review security prompts and credentials.
• Failed authentication: Verify that the target account credentials are correct and that the account has permission to run as a different user.
• Task Scheduler invoking RunAs incorrectly: Update the task's RunAs settings to correct account or use a trusted admin account.
• Malware masquerading as RunAs: Run full system scan, verify location, and replace any suspicious binaries with clean copies from Microsoft.
• Outdated Windows components: Ensure Windows is up to date; install latest servicing stack and security patches.
• UAC policy misconfig: Adjust User Account Control or create allow/elevate rules for trusted tools only.

Related Processes