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Is that executable safe, or a threat?

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Executable Directory

Our ultimate directory of Windows PC executables.

What’s ru64.exe (Registry size usage reporter)? Is it safe or a virus?

The official "Microsoft Learn" website reports that the file ru64.exe is the 64-bit version of Registry Usage (RU), a command-line utility developed by Microsoft as part of the Sysinternals suite. This tool reports the registry space usage for a specified registry key, allowing users to analyze and troubleshoot registry bloat or performance issues.​

By default, RU recurses subkeys to show the total size of a key and its subkeys. It supports various command-line options, such as outputting results in CSV format, specifying subkey depth, and loading hive files for analysis.​

If you encounter ru64.exe on your system, it's likely being used for registry analysis or monitoring. Ensure that it's located in a trusted directory and is digitally signed by Microsoft Corporation to verify its authenticity.

Below are 4 simple steps you can take to see if the ru64.exe process is safe or malware.

  1. Scan the executable with Microsoft's built-in tech
  2. Find ru64.exe's publisher
  3. Search the executable's hash with VirusTotal
  4. Monitor the executable's behavior

Researched by Carl @ SpyShelter Labs

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A Trojan is a harmful software that pretends to be a legitimate program or file to deceive users into downloading it. It can steal personal information, damage files, or give hackers control over the infected device.

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More about ru64.exe on WINDOWS

Who makes ru64.exe (Registry size usage reporter)?

We’ve found Microsoft Corporation should be the publisher of ru64.exe.

How do we know? Our SpyShelter cybersecurity labs focuses on monitoring different types of Windows PC executables and their behaviors for our popular SpyShelter Antispyware software. Learn more about us, and how our cybersecurity team studies Windows PC executables/processes.

What does it mean if someone is the publisher of a PC .exe (executable or process)?

The publisher of an executable is the entity responsible for its distribution and authenticity. Most processes/executables on your PC should be signed. The signature on the executable should have been verified through a third party whose job it is to make sure the entity is who it says it is. Find an unsigned executable? You should consider scanning any completely unsigned .exe on your PC.

Last updated: April 16, 2025

Curious about other processes on your PC?
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Why should you trust us?

Our team at SpyShelter has been studying Windows PC executables for over 15 years, to help fight against spyware, malware, and other threats. SpyShelter has been featured in publications like The Register, PC Magazine, and many others. Now we’re working to share free, actionable, and easy to understand information about Windows executables (processes) with the world, to help as many people as possible keep their devices safe. Learn more about us on our "About SpyShelter” page.

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