What Is Rundll32.exe Process? Is It Safe or Trojan? [Everything You Need to Know]

Daisy updated on Mar 31, 2023 | Home > Knowledge Center

When you go through Windows Task Manager's list of running apps and services, you will find many unfamiliar or uncommon names. That's because Windows might be running a service it usually doesn't—for some particular operation.

However, this also allows hackers and malware attackers to disguise their malicious apps and processes with the name of these Windows services. That's why a lot of people wonder whether the rundll32.exe they are running is safe or Trojan.

To answer this question, we'll dive into the basics of rundll32.exe, what it does and whether it's safe or not. So, let's get started.

What Is Rundll32.exe Process?

Rundll32.exe is a process that is used to load and run DLLs. It is a Windows system file and can be found in the Windows directory. The rundll32.exe process is important because it ensures that the operating system, drivers, and applications are running smoothly together.

DLL stands for Dynamic Link Library. DLL file contains various routines and aspects required by Windows to run apps smoothly. And, rundll32 dictates how and when Windows is going to need those services.

That's why rundll32.exe is a vital part of Microsoft Windows, as it helps prompt basic functions by Windows. Here's how:

Step 1. Once you open an app that requires a particular DLL, Windows redirects the request to rundll32;

Step 2. Then rundll32.exe will dictate that particular DLL, such as D3Dx9.dll, for games.

Therefore, rundll32.exe is not only important but a very important aspect of Windows processes. It allows your computer to run smoothly. And, as the name suggests, rundll32 stands for:

  • Run – as it dictates which DLL to run;
  • DLL – as it controls all the DLL files;
  • Numeric 32 means it uses DLLs in the 32-bit architecture.

Therefore, it allows Windows to pick the right DLL file from the library and run it for the current process or requirement at hand.

Is Rundll32.Exe Safe? Or Trojan?

Since rundll32.exe is so important, it's also one of the most exploited processes in Windows. A lot of malware and other malicious programs hide as rundll32.exe, as Windows simply wouldn't allow a user to terminate the process through the task manager.

However, a constantly running rundll32.exe isn't an omen of a virus, either. It could also mean that a process or app requires DLL files at all times. However, there are ways to tell whether your rundll32.exe is safe. Here are a few ways:

  • See if the task manager has two of rundll32. exes running;
  • See if the task manager is running rundll32.exe at all when DLLs aren't required;
  • See if the rundll32 file is in the Windows folder.

All these methods can tell you whether the rundlll32.exe you're running is safe or not. But, if you have more than one running in your task manager, then it's more than likely a malware or Trojan virus.

How To Find Out If Rundll32 Is Safe?

There are two ways to tell whether your rundll32 is safe or a virus. The most obvious way is to check whether you have two rundll32.exes running in the task manager. If not, then you can check whether the rundll32.exe location lands in the Windows/Windows System32 folder. Here's how:

Step 1. Open "Task Manager."

Step 2. Switch to the Details tab.

Step 3. Locate Rundll32.exe.

Step 4. Right-click on it and click "Open file location."

Open file location

Step 5. Check the filename and address.

check filename and address

If the running file is located in the system32 folder, then it's safe. If it opens in another folder or unfamiliar location, then it's a virus. So, it's better to try and delete it. Or to remove it using the best free virus removal.


There are other ways to tell whether your rundll32.exe is safe or not, and that's by conducting a full-system virus scan. If rundll.32.exe is infected by a virus, Windows Defender will likely detect it and quarantine it—or remove the virus.

However, it's important to understand that Rundll32.exe is a necessary process, and you must allow it to continue if it's safe—or sits in the System32 folder.

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Updated by Larissa

Larissa has rich experience in writing technical articles. After joining EaseUS, she frantically learned about data recovery, disk partitioning, data backup, and other related knowledge. Now she is able to master the relevant content proficiently and write effective step-by-step guides on computer issues.

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Written by Daisy

Daisy is the Senior editor of the writing team for EaseUS. She has been working in EaseUS for over ten years, starting from a technical writer to a team leader of the content group. As a professional author for over 10 years, she writes a lot to help people overcome their tech troubles.

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