Waltonchain, an ambitious project aimed at achieving Value Internet of Things [VOIT], was under attack causing the network to be forked, according to an official announcement.
The coordinated attack that took place on the mainnet allowed the attacker to increase his/her “coinage score and mine many blocks concurrently from blockheight 175,368”. The “KIRINMINER POOL” and the devs caught this early on, causing the breach to be fixed.
The team at Waltonchain stated that parts of the code that had vulnerability were rewritten and rolled out earlier on June 29, 2019 UTC 8+. The announcement further added:
“Waltonchain Mainnet has been upgraded at block No. 175,366. We hereby inform miners to download the updated source code and use the new full-node wallet to continue mining on the upgraded Waltonchain Mainnet. From block No. 175,366, miners will not be able to receive mining rewards without the new wallet software.”