Fraudsters are stealing millions of dollars worth of assets from crypto traders by posing as support for the American crypto exchange Coinbase. One of the victims lost $1.7 million worth of cryptocurrency.

Tegan Kline, co-founder of Edge & Node, said a friend of hers lost assets after an unknown person tricked the man into revealing his private key. The attacker contacted the victim by phone, posing as a Coinbase employee.

The scammer then sent the victim an email claiming to be from Coinbase security. The author of the email identified himself as David Brown, stating that if the user had received the email, it meant they had spoken to an “official Coinbase representative.” The scammer managed to convince the man that unauthorized transactions were being made from his account.

To solve the problem, the victim was redirected to a website controlled by the scammers. According to the victim, he suspected that the website might be unsafe, so he entered only part of the key phrase and did not send it. Despite this, the criminals were able to withdraw crypto assets from the victim’s wallet.

Hiro Systems CEO Alex Miller warns that scammers only need part of your seed phrase to figure out the rest. Miller says he, too, has been targeted by fake Coinbase employees trying to access his account.

This isn’t the first time that scammers have impersonated Coinbase customer support: similar attacks on users occurred last year. PeckShield analysts recently reported that hackers stole $176.2 million from cryptocurrency platforms in June, with phishing becoming a favorite method of stealing crypto assets.