Why is PerfPowerServices using my microphone?

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Level 1

17 points

Why is PerfPowerServices using my microphone?

This question has already been asked by cisforcojo in https://discussions.apple.com/thread/251424972 on Jun 3, 2020. Unfortunately that thread cannot be replied to and instead suggests to "ask the question again to resume the discussion". I am not sure how much sense this makes.

Like the original author I also use the app OverSight which uses a configurable rulebase to determine which processes will be allowed to use the microphone or camera. Since I updated to BigSur, Oversight has notified me that the suspicious process from the original post (/usr/libexec/PerfPowerServices) has made my microphone active. Even worse, it does so although there is no matching OverSight rule which would usually be required.

2021-01-03 02:20:50 +0000: Audio Device became active (Built-in Microphone, process: PerfPowerServices, /usr/libexec/PerfPowerServices)

I was not awake at that time so I can safely say that this happened while the Mac was on standby.

I would appreciate if you Apple guys could elaborate a bit on what might cause this behaviour which seems double-sketchy. However the issue might also be with OverSight.

macOS 11.1

Mac mini, macOS 10.12

Posted on Jan 3, 2021 4:00 AM

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Answer 1

Barney-15E

Level 10

122,168 points

Jan 3, 2021 6:48 AM in response to ststefa

I would appreciate if you Apple guys could elaborate a bit on what might cause this behaviour which seems double-sketchy. However the issue might also be with OverSight.

No Apple guys (or gals) here. Just users like yourself.

PerfPowerServices "manages structured log archives that enable retrieval of system power and performance data."

Could it have powered it on to check log some data? I don't know. Maybe it was just the app misunderstanding what had happened.

You can sometimes find out what something is by searching the manual pages in Terminal. For example, this will bring up the man page for that process. Not all of them have a man page, and many are quite spartan like this one.

man PerfPowerServices

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Answer 2

ststefa Author

Level 1

17 points

Jan 3, 2021 7:06 AM in response to Barney-15E

Thanks for pointing me to the man page! I would not have thought that such exists for this kind of proprietary stuff. Although the content is not massively useful at least it gives some blurry justification about the purpose of the process. Still I fail to see why it needs the microphone for that ;). I think if Apple continues like that there will be an interesting new field for hardware hacking.

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Answer 3

Barney-15E

Level 10

122,168 points

Jan 3, 2021 7:19 AM in response to ststefa

The microphone uses power and would cause some performance affect on the system and other things on it.

But, still, I would guess it is the overbearing app incorrectly interpreting what happened.

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Why is PerfPowerServices using my microphone?

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