The U.S.

Internal Revenue Service is warning crypto holders that scammers are mailing counterfeit letters to some taxpayers in an effort to steal their digital assets or data, according to Bloomberg.

Letters may direct taxpayers to register for a fake "Digital Asset Compliance Portal," the IRS said, adding that no such portal exists, according to the report.

The agency has also said to avoid scanning QR codes or taking calls from people seeking payment.

While phishing and other digital scams are nothing new in the crypto industry, the use of physical mail appears to be a new tactic.