[cormacrelf]

Probably a good idea to turn off auto-update from Transmission's preferences and only use

    brew update && brew cask install --force transmission

to update. Even though they're also meant to be checksummed, I can't know whether an attacker also compromised the checksum mechanism.

[minhoryang]

Do we need to --force just for updating?

[millak]

Yep, brew cask will just tell you that Transmission is already installed without --force.