What Is COM Surrogate and dllhost.exe?

What Is COM Surrogate and dllhost.exe?.

Viewing a list of processes on a Windows computer using Task Manager is a recipe for paranoia. A lot of programs run with strange sounds, and usually you cannot find out what is good and what is bad for your computer. The dllhost.exe COM replacer is just one such process, but it is much more mundane than you might think.

What Is COM Surrogate (dllhost.exe)?

COM is short for Component Object Model. This is what Microsoft introduced in the early 90s to make it easier for programmers to extend the functionality of existing software. In other words, it’s like a plugin system that lets you add new functionality to existing programs like Windows Explorer.

This is great for dynamically enhancing a program’s capabilities, but it has a downside. If the COM module is poorly programmed or malfunctions for some reason, this also leads to the failure of the program to which it is connected. This is because both COM and the main program run as one process.

This is where COM surrogates come in. This approach allows COM to run in its own separate process as if it were its own program. The main program and COM surrogate processes communicate with each other as needed. But if the COM surrogate fails for any reason, it will lead to nothing but its own process. This makes the system as a whole more stable.

Is COM Surrogate (dllhost.exe) Safe?

How secure is dllhost.exe is a tricky question because it will depend on the specific COM running. They usually host harmless processes that perform useful actions, but it is likely that poorly coded COM or malware combined with a COM surrogate structure could cause damage or execute malicious code.

Finding COM Surrogateâ€™s Location

The only valid location for the dllhost.exe file is inside the System32 folder in the Windows folder. The default path is Windows> System32 on the system drive. The system drive is usually drive C. If you find this file elsewhere, it might be a virus. So be sure to scan!

Checking COM Surrogateâ€™s Legitimacy

As mentioned above, the COM surrogate you see in the Task Manager is not a specific application, it is just a wrapper around another process. Since we cannot easily understand what is actually going on in a particular COM surrogate process, the only real way to check for suspicious behavior is to use an antivirus program.

Of course, you should still run your antivirus program at regular intervals, but if you see a COM surrogate that is using a lot of resources or causing system instability, that might be one explanation.

Again, the COM surrogate process in question might just be erroneous and not malicious. If you have saved all your documents, you can try to force terminate the given COM surrogate process to find out what it is doing. Anything that crashes or freezes immediately after the process terminates is probably a related program. Once you find the most likely culprit, restart your computer.

Fixing COM Surrogate Errors

COM surrogate errors do happen from time to time and are probably the most common reason people look for the process name in the first place. The “COM surrogate has stopped working” error may seem mysterious at first. Now that you know what a COM surrogate is doing, it is obvious that the process is indeed doing its job.

The COM surrogate is designed to protect program extensions from crashing the main process they are extending, so the cause of this error can be traced back to which COM module was running in the surrogate.

There is no easy way to find out which COM it was, as the surrogate itself masks the specific COM within it. There are several likely suspects:

Third party video codecs are outdated. If you have them, delete or update them.
Your antivirus program may interfere with the COM surrogate. Disable it temporarily. If this does seem to be a problem, switch to a different antivirus or try updating yours to the latest version, if applicable.
Check your disk for errors using a utility such as CHKDSK.
Check your system files for corruption with the System File Checker tool.
Roll back the latest driver updates or update your display and, in particular, your printer drivers. Try using both the manufacturer’s standard GPU driver and the OEM version if applicable to your computer.

If you want to know how to determine exactly which COM port is running in a surrogate, there is a more technical solution.

Checking Inside a COM Surrogate Process With Process Explorer

Microsoft has an additional utility known as Process Explorer. This is useful for a lot of things. For example, if you were told that you can delete a folder because it is open in a program, you can use Process Explorer to find out which program it is and force it to close without restarting your entire computer.

Just download and launch Process Explorer and you will see a window like this:

Remember that COM Surrogate is actually called dllhost.exe. So find that and hover your mouse over the entry. In the pop-up window, you will see which DLL file is being hosted. This usually gives you enough information to know which program is connected to it. If it’s not obvious from the DLL name, you can google for a more accurate answer.

COM On Over for a Party

As a reminder, you now know what COM is, what a COM surrogate does, how to fix the most common problems, and how to determine which COM you are dealing with. Which hopefully fixed your COM related problems forever.

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