As of 05:44 UTC Thursday, visitors to the site were greeted with “This site can’t be reached.” An entity or person who who uses the pseudonym Cobra who has been the site’s operator but whose current affiliation isn’t clear, said the site might be down while they were looking into the hack.

Earlier Thursday, a pop-up message blocked the homepage screen, inviting visitors to send money to a bitcoin wallet. The funds will be doubled and sent back, the message said. The message claims it is because the Bitcoin Foundation is “giving back to the community.”

The message said only the first 10,000 users could take advantage of the offer. The message included a QR code for the wallet as well as its address. All other site functionality at the time was limited as users couldn’t get around the message.

These messages are associated with giveaway scams; these schemes give false promises of doubling one’s funds after sending an initial amount to a wallet address via QR code. Victims, in fact, receive nothing in return and lose the crypto they sent.