Bitcoin hackers have claimed two more victims, with exchange Flexcoin announcing its virtual vault has been drained and that it will be ceasing operations immediately, while Poloneix confessed a security lapse of its own. "On March 2nd 2014 Flexcoin was attacked and robbed of all coins in the hot wallet" the company announced. "The attacker made off with 896 BTC," Flexcoin says, which works out to around $600,000 at today's rate.
According to Flexcoin, the stolen coins were divided between two different addresses.
"As Flexcoin does not have the resources, assets, or otherwise to come back from this loss," the company admits, "we are closing our doors immediately." Those who had stored their bitcoins with the exchange in cold storage are safe, since they were held offline and inaccessible to the hackers.
However, everybody else is out of luck, with Flexcoin pointing to its terms of service in which it sheds itself of any responsibility for lost or stolen coins.
It's not the only hack that has been revealed today, with Poloniex admitting that around 12.3-percent of its bitcoin holdings had been stolen. Worth an estimated $50,000, the theft was carried out through an exploit of how Poloniex's systems handled negative balances, which allowed multiple simultaneous withdrawals to temporarily fool the exchange.
Poloniex has frozen withdrawals and markets, and will be sharing the loss among all users since the company does not currently have the funds to cover the shortfall in balance.
The thefts follow the high-profile collapse of Mt. Gox, the bitcoin exchange which was taken down recently after its entire reserve was stolen. The company has filed for bankruptcy, with more than $63m in debt.