https://utpstag.microsoftcrmportals.com/forums/support-forum/e331ee11-24c4-ef11-95f5-000d3a08b049

Coinbase generally does not make unsolicited calls to customers at +1-855-*998-0300. If you receive a call claiming to be from Coinbase without prior contact, exercise caution as it may be a phishing attempt or scam.