[Solution] What Is Dllhost.exe and Why It Consumes CPU?

Dllhost.exe Process Information

Dllhost.exe is the component to run COM+ so as to drive web and FTP server. It is created to manage DLL for the coordination among build-in controls, drivers, software and hardware, so that the system will be able to resist malicious infiltration. To put it plain, dllhost.exe will occur when running security utilities and dealing with connections.

The information chart is enough to answer the question as to “is dllhost.exe a virus”. However, the below scenarios do make PC users concerned:

1. Dllhost.exe starts hogging CPU memory when browsing/watching/viewing jpegs, media files (.mp4 etc.); at times there is only one instance of dllhost.exe, other times there are multiple instances.
2. Dllhost.exe (sometimes only one instance, other times multiple instances) gobbles up computer's entire CPU memory resulting in a crash/error message.
3. The security settings in IE keep getting changed, preventing users from downloading software.
4. Desktop background would randomly change.
5. Access to Guest account is denied.
6. Installed anti-virus programs give away alert message saying “COM Surrogate has stopped working” or “a buffer overflow was detected and blocked on your computer” with details attached:

Process: C:\Windows\system32\DllHost.exe
Process description: Com Surrogate
Use of space in Windows Vista: About ~7500K

Causes of Dllhost.exe Problem

The cause of the above listed scenarios is also open to virus affection due to its capability of coordinating dll operation; out of which, attackers manages to collect information on system configuration and online whereabouts for broader spread of vicious codes. Other causes include:

1. IIS deadlock
2. Open Database
3. thumbnail preview error

Below is the instruction to show how to fix dllhost.exe problem caused by IIS deadlock, persistent request, virus affection and thumbnail previews respectively. If you are not that technically sound to perform the below steps, it is advisable to contact VilmaTech Online Support and get specialized technical help.

How to Fix High CPU Consumption by Dllhost.exe Process 

One - IIS deadlock issue.

1. Go to “Find deadlock module” and set “wblock” as “yes”.
2. Also set file directory, d:\test for example, and “logblock.htm” under log catalogue.
3. Restart IIS and record ACCESS file in “logblock.htm”.
4. Check the last 10 ACCESS files (“**COUNT.MDB” and the like) recorded in “logblock.htm” if CPU rises high again.
5. Move counter files that you suspect to be culprit to Dustbin temporarily.
6. Restart IIS.

Two - persistent request.

1. Bring up Run box and type “iisreset -stop”.
2. Hit Enter key will solve the problem.

Three – virus affection.

1. Note down the flagged directory of the detected infection.
2. Unveil hidden files and folders to remove any item named after the virus in the detected directory.
3. Go to C:\windows\winstart.bat, C:\windows\wininit.ini and C:\windows\Autoexec.bat to remove any suspicious items.
4. Go to C:\Windows\System32 to remove any suspicious items.

Four – thumbnail previews.

1. Restore the recently updated item to previous version right prior to the occurrence of dllhost.exe problem.
2. Delete the file that causes computer freeze temporarily in the middle of the download.
3. Disable thumbnail preview.

Consequence of Dllhost.exe Problems

1. Browser would crash.  
2. Unfamiliar web page error might emerge to stop surfing.
3. Computer would freeze occasionally.
4. It takes longer to load the intended web page.
5. Computer may get stuck in the middle of operation.
6. Email accounts might fall into spreading virulent codes without authorization.
7. Backdoor might be brought into being for additional infiltration.
8. Web vulnerability can be triggered to be exploited readily by other destructive infections.
9. Stored information can be collected without knowledge.

For more detailed information about dllhost.exe, one might need to read the following listed reference. Should you have any question or difficulty in dealing with dllhost.exe problem, please do feel free to contact the recommended PC Security Center and get quick fix.

Reference:

How to Fix High CPU Consumption by Dllhost Process – Global PC Support Center

Component Object Model – WikiPedia

Dynamic Link Library – WikiPedia