The unauthorized transaction included a message reading "we are whitehats. contact us on chain", suggesting the possibility that the withdrawal was in fact well-intentioned security researchers aiming to "rescue" funds after discovering they were vulnerable and then return them to a secure wallet. However, as of the afternoon on September 6, Blockstream had only said that they were "working on contacting" the "purported white-hat hackers".
Blockstream pauses Liquid Network after attackers claiming to be whitehats take 4,000 BTC (~$320 million)
An unauthorized withdrawal of 3,998.5 BTC (~$320 million) from the Liquid Network, a bitcoin sidechain, prompted a network halt. By disabling nodes that bridge between Liquid and the bitcoin mainchain, attackers are limited in their ability to cash out via bridge. Blockstream, the developers of Liquid Network, also said they had contacted exchanges to ask them to pause LBTC deposits and withdrawals, cutting off another avenue.