The .exe extension on a filename indicates an executable file. Executable files may, in some cases, harm your computer. Therefore, please read below to decide for yourself whether the dllhost.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.
Description: The original dllhost.exe from Microsoft is an important part of Windows, but often causes problems. The file dllhost.exe is located in the C:\Windows\System32 folder.
Known file sizes on Windows 10/8/7/XP are 7,168 bytes (49% of all occurrences), 5,120 bytes and 19 more variants.
The dllhost.exe file is a Windows system file. The program has no visible window. It is a Microsoft signed file. Therefore the technical security rating is 4% dangerous; however you should also read the user reviews.
Recommended: Identify dllhost.exe related errors
Is dllhost.exe a virus? No, it is not. The true dllhost.exe file is a safe Microsoft Windows system process, called "COM Surrogate".
However, writers of malware programs, such as viruses, worms, and Trojans deliberately give their processes the same file name to escape detection. Viruses with the same file name are such as WORM_INJECT.OB or WORM_VB.GZP (detected by TrendMicro), and W32.SillyFDC or W32.Fontra (detected by Symantec).
To ensure that no rogue dllhost.exe is running on your PC, click here to run a Free Malware Scan.
How to recognize suspicious variants?
If dllhost.exe is located in a subfolder of C:\Windows, the security rating is 4% dangerous. The file size is 7,168 bytes (82% of all occurrences), 17,760 bytes and 4 more variants. The program has no visible window. It is a Windows system file. Dllhost.exe is a trustworthy file from Microsoft.
If dllhost.exe is located in a subfolder of the user's profile folder, the security rating is 63% dangerous. The file size is 417,792 bytes (46% of all occurrences), 3,748,645 bytes and 5 more variants. There is no information about the author of the file. Dllhost.exe is not a Windows core file. The process starts when Windows starts (see Registry key: MACHINE\Run, MACHINE\User Shell Folders, Run). The program is not visible. Dllhost.exe is able to monitor applications and manipulate other programs.
If dllhost.exe is located in the C:\Windows folder, the security rating is 67% dangerous. The file size is 762,368 bytes (42% of all occurrences), 1,105,920 bytes, 19,456 bytes, 671,744 bytes or 431,132 bytes.
If dllhost.exe is located in a subfolder of "C:\Program Files\Common Files", the security rating is 29% dangerous. The file size is 13,608 bytes.
If dllhost.exe is located in a subfolder of "C:\Program Files", the security rating is 43% dangerous. The file size is 5,120 bytes (25% of all occurrences), 4,096 bytes, 417,792 bytes or 13,179,660 bytes.
If dllhost.exe is located in a subfolder of C:\Windows\System32, the security rating is 95% dangerous. The file size is 370,688 bytes (50% of all occurrences) or 10,240 bytes.
If dllhost.exe is located in a subfolder of Windows folder for temporary files, the security rating is 56% dangerous. The file size is 2,049,024 bytes.
If dllhost.exe is located in C:\, the security rating is 40% dangerous. The file size is 67,072 bytes.
External information from Paul Collins:
Important: Some malware disguises itself as dllhost.exe, particularly when not located in the C:\Windows\System32 folder. Therefore, you should check the dllhost.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.
A clean and tidy computer is the key requirement for avoiding problems with dllhost. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.
Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.
To help you analyze the dllhost.exe process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.