/usr/share/X11/xorg.conf.d/50-vmmouse.conf is in xserver-xorg-input-vmmouse 1:12.8.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | Section "InputClass"
Identifier "vmmouse"
MatchIsPointer "on"
MatchTag "vmmouse"
Driver "vmmouse"
EndSection
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