What is mwac?

The genuine mwac.sys file is a software component of MBAMWebAccessControl by Malwarebytes.
"Mwac.sys" is a Windows driver, set to run at Windows startup, installed by the paid (or free trial) version of Malwarebytes 3.0, or Malwarebytes Anti-Malware in earlier versions. (For MB 3.0 they combined their Anti-Malware, Anti-Exploit, and Endpoint Security products.) It resides in "C:\Windows\System32\drivers" and only uninstalls if the Control Panel is used to uninstall "Malwarebytes Anti-Malware" completely. The Premium version of Malwarebytes provides four layers of real-time protection. "Mwac.sys" provides "Web Protection," preventing connections to websites known to be malicious or compromised. In early 2017, users of MB 3.0.4 and 3.0.5 were reporting Web Protection turning itself off, and sometimes BSOD's. Consult Malwarebytes' extensive user forums about this and other issues. Founded in 2008 by CEO Marcin Kleczynski and Bruce Harrison, Malwarebytes has gained wide recognition for its products and their rapid customer base expansion recently led to relocating their headquarters to Santa Clara, CA, USA.

MWAC stands for Malwarebytes Web Access Control

Mwac.sys is a Windows driver. A driver is a small software program that allows your computer to communicate with hardware or connected devices. This means that a driver has direct access to the internals of the operating system, hardware etc. The free file information forum can help you determine if mwac.sys is a Windows system file or if it belongs to an application that you can trust.

Run a free scan to check for mwac drivers in need of updating

Mwac.sys file information

The process known as Malwarebytes Web Access Control or Malwarebytes Web Protection or MBAMWebAccessControl belongs to software MBAMWebAccessControl or MBAMWebProtection or Malwarebytes Anti-Malware version or Malwarebytes Web Access Control by Malwarebytes (

Description: Mwac.sys is not essential for Windows and will often cause problems. Mwac.sys is located in the C:\Windows\System32\drivers folder. The file size on Windows 10/8/7/XP is 51,928 bytes. 
The driver can be started or stopped from Services in the Control Panel or by other programs. The program has no visible window. The file is a Verisign signed file. The file is certified by a trustworthy company. The service has no detailed description. Mwac.sys is not a Windows core file. mwac.sys appears to be a compressed file. Therefore the technical security rating is 20% dangerous; but you should also compare this rating with the user reviews.

Recommended: Identify mwac.sys related errors

Important: Some malware camouflages itself as mwac.sys. Therefore, you should check the mwac.sys 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.


User Comments

My computer failed and had to reboot. mwac.sys was identified as the cause of the failure, although I don't know why.
  Phil Finney  

Summary: Average user rating of mwac.sys: based on 1 vote with 1 user comment. One user thinks it's neither essential nor dangerous.

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Best practices for resolving mwac issues

A clean and tidy computer is the key requirement for avoiding problems with mwac. This means running a scan for malware, cleaning your hard drive using 1cleanmgr and 2sfc /scannow, 3uninstalling programs that you no longer need, checking for Autostart programs (using 4msconfig) and enabling Windows' 5Automatic 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 6resmon 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 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the mwac.sys process on your computer, the following programs have proven to be helpful: ASecurity 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. BMalwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

mwac.sys [all]