Last Saturday on February 19th, online attackers stole hundreds 0f Non-Fungible-Tokens (NFTs) from OpenSea users, running a late-night panic among the users. Up to 254 NFTs were stolen, most of which occurred from 5 p.m. to 8 p.m., racking up a grand total of 1.7 million dollars.

NFTs are a form of cryptocurrency that involves putting a price tag on a unique image that cannot be replicated, similar to a trading card where there’s only one of each type. OpenSea, a company valued at $13 billion, has become the largest website for NFT purchasing with high security and low complication.

Many of the attack details remain unknown. However, the attackers stole the NFTs from users by abusing a loophole in the Wyvern Protocol (an open-source standard underlying NFT contracts.) Authorities believe the attack likely occurred through a partial signing of the victim’s contracts, followed by the attackers finishing the signing, handing over the asset to their own accounts. According to OpenSea CEO, “We don’t believe it’s connected to the OpenSea website.” OpenSea was in the midst of updating contract systems during the time of the attack. Skepticism is still in the air; more information will make the issue clear as time goes on.