Hackers, using a sophisticated hack, managed to falsify the currency’s ledger and stole 388,000 coins worth $17.5m from online exchanges.
The method used by the malicious miners is known as a ‘51% attack’. The attacker gains control of the majority of the network’s total computing power. With this dominant level of computer power, it enables the hacker to manipulate the blockchain ledger on which transactions are recorded, and to then ’reverse their own transactions’ and spend the same digital coins again.
According to the website Bitcoinist, the records of a digital wallet show hackers made fraudulent deposits, in which the money never ended up with the recipient exchange:
“The attacker sends a particular number of BTG tokens to an exchange, trades them for another coin and makes a withdrawal. The hacker then returns those same coins in his/her wallet, hence the double-spending problem. Thus, the attacker can spend and hold the same coins at the same time. Looking at the image above, if all 76 transactions were indeed part of the hack, then the hacker has stolen about $18 million based on the current BTG price.”
The price of Bitcoin Gold fell slightly on news of the attack, but so far there has been no sign of panic selling.