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MBAMService High CPU

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I have been trialling MB and have just purchased the Home Premium version.

MBAMService sits at a near-constant 13% CPU - why? What is it doing? The scheduled scan is not due to run until 2am (it is now 8pm) and a full manual scan was done days ago. Ihave not been installing any new s/w or any such thing.

Windows 7 Ult x64, Firefox and PaleMoon browsers running, with Thunderbird - AND Avast. I am not clear as to whether MB makes Avast unnecessary or if the two can - or can not  - be running at the same time. MB, fully up-to-date.

Thanks in anticipation.

[This did not appear to be posted - sorry if it appears twice]

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***This is an automated reply***


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Greetings and welcome :)

I'm sorry to hear that you're having problems with the performance of Malwarebytes 3.  We'll do our best to resolve the problem so that the software works to protect you as efficiently and quietly as possible.

While Malwarebytes 3 does provide sufficient protection on its own to prevent infection from malware, exploits and other web based threats it should be possible to run it alongside an active antivirus as it was designed to be compatible with other security software solutions.

First off, just to eliminate it as a variable please try disabling Avast! Antivirus if you can just to determine if that might be the cause.  If it is, we should be able to configure exclusions between the two products to get them to work alongside each other without conflict but I just want to know first off if that's what's causing the problem or not before having you go through that process.

Please let me know how that goes then we will proceed with the next steps.

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Sorry for the delay, and thanks for your reply, but I have been watching what MBAMService is doing. It does eventually quieten down to near-zero CPU. But, it comes back to being a constant 13% quite frequently.

I have tried disabling Avast (e.g. for 10 mins) but this has no immediate effect. I might try uninstalling Avast. I should add that I am a s/w developer and am thus creating DLLs and exe files very frequently. Could this be causing MB to be, as it were, constantly on the alert or scanning? I will try to see if the 13% correlates with dev activity.

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3 minutes ago, jasjas said:

I should add that I am a s/w developer and am thus creating DLLs and exe files very frequently. Could this be causing MB to be, as it were, constantly on the alert or scanning? I will try to see if the 13% correlates with dev activity.

Yes, it certainly could assuming you're loading the files into memory.  While Malwarebytes doesn't include on-access scanning (in other words, it does not scan files as they are created on disk or downloaded), it does include on-execution scanning meaning that if the files enter into memory as processes/modules (even if only loaded into/injected into other processes) then Malwarebytes will scan that activity.

Additionally, if you're doing anything that generates a lot of web traffic, that might also account for some of the CPU usage as Malwarebytes web protection component checks connections to determine if any of them are to sites contained within its blacklist/databases.

There's also the more recent additions to Malwarebytes, exploit protection and ransomware protection.  If any activity on your system causes those components to monitor what's going on more thoroughly, then that could also account for it.  For example, as mentioned previously, loading modules (like DLLs, for example) into other processes, this is something which might trigger exploit protection to become more intensive/more active, and likewise if anything you're doing is modifying/deleting many files on disk, ransomware protection might become more active/utilize more resources as it monitors the activity to verify that it isn't malicious.  Beyond that of course is the possibility of a conflict.  You mentioned Avast! and while I don't currently know of any, it is possible that there is some kind of conflict/performance issue there between the latest version of Malwarebytes and some component(s) in Avast! that might be causing it, especially if any components of Avast! remain active even when its primary protection has been disabled.

That said, if you haven't already, I'd definitely recommend creating exclusions between Avast! and Malwarebytes to help eliminate the possibility of any potential conflicts.  A list of files/processes to be excluded for Malwarebytes 3 in Avast! can be found in this post and as for excluding Avast! from Malwarebytes, I'd recommend at least excluding Avast!'s Program Files folder and any executables located elsewhere which belong to it (for example, if Avast! stores/installs any services/executables inside the Windows directory or elsewhere) and you might also consider excluding whatever location Avast! uses for storing its databases and configuration data (most likely a sub-folder of C:\ProgramData).

I hope that helps.  Please let us know if it does not and if there are any further issues.

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  • 2 weeks later...

Last week, I removed Avast entirely and have not seen a repetition of the "13%" problem - CPU levels have been normal, as far as I know (the PC is always on). I am now running with only Malwarebytes Premium as the only protection. Google searches leave me confused as to whether this is adequate or not. I don't want to install anything else if there is a risk of the same high-CPU problem. What would you advise?

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Yes, Malwarebytes alone is sufficient, however Malwarebytes is designed to run alongside other security software, so if you would prefer to have an AV as an additional layer of protection and want another free option you may install Microsoft Security Essentials, Avira, Bitdefender Free or Kaspersky Free.

I will advise our product team of the issue you encountered with Avast! so that they may investigate and hopefully fix it, assuming it may be fixed on our side.

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  • 4 weeks later...

With MB as the only AV program running, there have since been numerous occasions where MBAMService takes up a steady 13% CPU - such as now. This goes on for many, many hours - at a guess 6, 8 or more, at a time. I have never timed it. But, it is becoming difficult to cope with. The ambient temperature where I am is high (28 deg +) and the laptop fan regularly comes on and, when it does, MBAMService is usually seen at 13%.

I am almost at the point of uninstalling this program completely and requesting a refund, as it is not viable to continue long-term in this way. Is there no logging or diagnostics that might tell why this program is taking up so much processing time, so constantly and so often?

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