osx - Permission problems with /usr/local/bin and /usr/local/share -

i'm using os x yosemite in fresh macbook. installed homebrew , essential packages, having moved new computer recently.

i noticed once in while linking errors when install new brew packages. reason, permissions of /usr/local/bin , /usr/local/share keeps changing root:wheel after did chmod andchgrp several times make fp:admin (fp being username).

take note, fixes permissions time, allowing me install new brew packages, , changes root:wheel automatically @ random (at least per observation).

been trying google answer no avail. thoughts @ might wrong setup? appreciate insights. thanks!

you using sophos chance?

via https://apple.stackexchange.com/questions/178760/how-to-figure-out-what-is-causing-the-ownership-of-usr-local-to-change-from-my

"i had exact same issue, , turns out sophos auto-update blame. figured out running: sudo fs_usage | grep "usr/local"