macOS – What Is Silhouette

macos

I have a process called silhouette running on 10.13 (apparently the executable file is located in /usr/libexec/). It is extremely mysterious, I found no information whatsoever on the Internet regarding this process. Even databases of macOS processes would not mention it.

The CPU load of silhouette is extremely low, it would go totally unnoticed if not for one line in the Activity Monitor. It does not seem to establish network connections but I haven’t monitored it enough to be sure.

What is this process and what is it doing?

Best Answer

man silhouette reports (rather unhelpfully):

silhouette -- generate local topics on the device.

The daemon is launched by /System/Library/LaunchAgents/com.apple.coreparsec.silhouette.plist which is part of CoreParsec, the private framework that is part of Siri's backend.

strings /usr/libexec/silhouette yields a lot of method names related to machine learning: scoring bins, bloom filters, normalization routines, false positives, etc.

Absent further documentation from Apple, it's reasonable to conclude that this daemon is part of Siri's infrastructure. "Local topics" has a specific meaning in machine learning (usually in context of clustering algorithms), though I'm not sure if it's being used in that context or not.

It is for sure not malware, if that's what you're concerned about.

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