iMac weirdly restarting unexpectedly

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Level 1

4 points

iMac weirdly restarting unexpectedly

Hi everyone,

In our client site, there has an iMac which often restarted unexpectedly. We already tried with 1) Reinstall MacOS from scratch, 2) only install the work app, 3) monitoring the resource usage, 4) Apple Hardware test. So far most of the works we also tried but somehow the issue still existing, we did not see RAM overuse or CPU overheat, in Console App no logs we can found related to crashing.

Recently we have found from Apple community that someone has created a tool "EtreCheck" which is good for Mac checking. We have tried on it but from the report I am not fully sure if it is able to identify the root cause. As of now we can only advising the user to keep the iMac regularly restart every day to reload the resource.

Much appreciated for yours time to read on this article and your times to help on analyse the report's details, we are stuck on dead loop and no idea what we can do further unless informing the client to replace the iMac, but the iMac is just 4 years old and still young in my mind...

Best regards,

Werner

EtreCheck report

iMac (2017 – 2020)

Posted on Sep 14, 2025 11:22 PM

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Answer 1

Top-ranking reply

Owl-53

Level 10

100,501 points

Sep 15, 2025 02:07 AM in response to WernerYue

Third Party Security Software

There are no known Windows-like Viruses in the wild that self replicate and affect macOS, because of the underling UNIX Foundation and Permission Limitation.

The Operating System resides in a Sealed and Read Only Volume that cannot be opened by the User nor by Third Party Applications.

The Only thing this Antivirus software is protecting is the Bank Account of the Developers and for zero return to the User aside from the problems this software creates.

Security. Built right in

Mac app security enhancements

The Built in Security is all that is required to protect the computer.

Protecting against malware in macOS

Sophos

System Extensions:

[Running] networkextension - version 10.10.3 (Sophos - installed 2025-08-06)

Application: /Applications/Sophos/Sophos Network Extension.app - version 10.10.3 (Sophos - installed 2025-08-06)

[Running] com.sophos.endpoint.scanextension - version 10.10.4 (Sophos - installed 2025-08-22)

Application: /Applications/Sophos/Sophos Detection.app - version 10.10.4 (Sophos - installed 2025-08-22)

Description: Scanning Services

[Not Loaded] TransparentProxyTestExtension - version 10.10.3 (Sophos - installed 2025-08-06)

Application: /Applications/Sophos/Tools/Sophos Transparent Proxy Test Tool.app - version 10.10.3 (Sophos - installed 2025-08-06)

[Not Loaded] ContentFilterTestExtension - version 10.10.3 (Sophos - installed 2025-08-06)

Application: /Applications/Sophos/Tools/Sophos Content Filter Test Tool.app - version 10.10.3 (Sophos - installed 2025-08-06)

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Answer 2

rkaufmann87

Level 10

148,116 points

Sep 15, 2025 07:53 AM in response to WernerYue

+1 on uninstalling Sophos per the developers instructions. After that has been done, please restart the computer in Safe Mode (use a USB wired keyboard!!!!!!) and then restart normally.

Next, run a fresh EtreCheck report and carefully analyze to see if ANYTHING from Sophos is left over. If it is completely gone then re-test the computer to see if the problem is solved. If there is evidence of parts of Sophos still present download FindAnyFile and have it look for anything with

Sophos

in it and have it remove those files. Then re-run Etrecheck and check again!

Moving forward never ever install any of the following types of third party apps as they are completely unnecessary and harmful to Mac OS.

Antivirus
Cleaning
Security
VPN
Maintenance

To keep Mac OS fast, secure and trouble free simply keep it up-to-date and restart the computer about 1x per week. Other than that please leave it alone!!! Mac OS is extremely secure and as mentioned is not affected by MS Windows malware or viruses.

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Answer 3

HWTech

Level 9

66,962 points

Sep 15, 2025 10:59 AM in response to WernerYue

From EtreCheck report:

2025-09-04 20:12:31 Kernel Panic (8 times)

First occurrence: 2025-09-02 05:37:47

Details:

panic(cpu 1 caller 0xfffffff01cbee6a0): x86 CPU CATERR detected

Panicked task 0xffffffdfd1732c40: 0 pages, 199 threads: pid 0: kernel_

task

This is the source of your crashes....the CPU CATastrophic ERRor. This indicates a hardware issue.

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Answer 4

HWTech

Level 9

66,962 points

Sep 17, 2025 05:17 PM in response to WernerYue

WernerYue wrote:

@hwtech Thank you for the advise, I tried googling this error message, should it be the CPU hardware problem?

It may be the CPU itself or perhaps the supporting Logic Board circuitry for the CPU.

@John Galt Thank you for the advising, somehow it is the client decision to have a paid anti-virus be installed on all company machines, on my mind sometimes Sophos also eat lots of resources on the work machine.

Since you are required to use an AV product, then I would suggest choosing MalwareBytes instead as it seems to be less problematic & invasive. I must note that it is easy to turn off the MalwareBytes real time scanner.

The other option would be to get an enterprise grade end point solution. I know my organization requires AV protection due to our Cyber Insurance and this seems to be working Ok without too many issue as we had using traditional AV solutions years ago (Norton/Symantec, Sophos, etc.). I do see it causing performance issues at times though....it is kind of what they do.

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Answer 5

John Galt

Level 10

153,754 points

Sep 15, 2025 12:50 PM in response to WernerYue

WernerYue wrote:

We already tried with 1) Reinstall MacOS from scratch, 2) only install the work app, ...

... followed by "anti-virus" junk?

Why people continue to fall for those scams after all these years beggars belief.

As bad as it is though, "Sophos" cannot cause hardware failure. Next time, don't reinstall the junk.

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Answer 6

WernerYue Author

Level 1

4 points

Sep 15, 2025 09:19 PM in response to WernerYue

Good day everyone,

@Owl-53 @rkaufmann87 Thank you for the kindly checking and advising! For next action, we will try uninstalling Sophos AV and re-run the EtreCheck tool. However in all of the work machines, they are also with Sophos AV running, somehow only that particular iMac get the issue that's why we have not think about Sophos affecting the machine.

We never setup Bootcamp on the client's Mac machines so not sure why it has listed the BootCamp stuff, will also have a look on it.

@hwtech Thank you for the advise, I tried googling this error message, should it be the CPU hardware problem?

@John Galt Thank you for the advising, somehow it is the client decision to have a paid anti-virus be installed on all company machines, on my mind sometimes Sophos also eat lots of resources on the work machine.

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