Sounds like a firmware default mining pool which produces BTC for the OEM - probably left in after a 'burn in testing peroid'.
Ask the OEM to confirm then ask how to flash thie firmware and change the defaults to a pool of YOUR choice.
This is weird, I wonder if this has happened to anyone else here.
The funny thing is that it changes the defaults of my pool to their pool, any experts want to chime in on how this might be happening?