In the early morning of December 23, the official Weibo of the public chain project NULS announced that the team account was hacked, and the hacker transferred 2,000,000 NULS from the account. Among them, 54853.34696095NULS has flowed into the trading market and cannot be traced. The announcement shows that the NULS team has decided to perform a hard fork at a height of 878,000. After the hard fork, 1451645.65303905NULS that has not entered the trading market will be destroyed in a permanent freeze to prevent it from continuing to flow into the market and causing losses to community members. According to the NULS team, the reason for this attack was due to a security vulnerability in the bottom layer of NULS 2.2. The team has fixed the vulnerability. In addition, the NULS team is preparing a hard copy procedure and has contacted the exchange to release a new version as soon as possible.