Hackers hijacked cryptocurrency trading platform CoinDash on Monday just as it was in the middle of its initial coin offering, or ICO. It’s the first known breach of an ICO, this season’s hottest fundraising method.

CoinDash, an Israeli startup, planned to raise capital by selling its own digital tokens in exchange for the cryptocurrency Ethereum, which is similar to Bitcoin. But just 13 minutes into the token sale, which began at 9 a.m. ET Monday, an “unknown perpetrator” hacked CoinDash’s website and changed the address for sending investments to a fake one, the company later announced on its website. That diverted millions of dollars in contributions to the attacker.

While the CoinDash ICO still managed to raise $6.4 million from early investors, the hacker stole $7 million worth of Ethereum before the company was forced to pull the plug on the token sale. Despite the losses, CoinDash promised to dole out its tokens accordingly to everyone who participated in the ICO before it was shut down, whether or not they sent funds to the correct address.

“Reminder: We are still under attack. Please do not send any [Ethereum] to any address, as the Token Sale has been terminated,” CoinDash said in the statement.