Verified blockchain security incidents with original evidence and historical event dates.
Description of the event: Bitstamp reported that multiple operating wallets were damaged, resulting in the loss of 19,000 bitcoins. The company was hacked by multiple phishing attacks in the months before the attack. An employee downloaded a malicious file that allowed an attacker to access the password of the company's hot wallet and the server including the wallet.dat file.
Description of the event: MintPal announce that the attacker stole 8 million VeriCoins ($1.8 million) from the company's hot wallet. The attacker exploited a vulnerability in its system that allowed them to bypass the security controls to withdraw funds.
Description of the event: Digital currency exchange Poloniex, which trades bitcoin and other popular digital currencies such as litecoin, namecoin and dogecoin, has lost 12.3% of its total bitcoin supply in an attack. The exchange took to Bitcoin Forum on 4th March to report it had been compromised by a previously unknown vulnerability in its coding.
Description of the event: MtGox was hacked. Losses totalled 850,000 BTC, worth $470m at the time.
Description of the event: On June 8, Feathercoin was attacked by 51%. Before the attack, Feathercoin's total computing power was 0.2GH/s, and during the time of the attack, the computing power doubled 7 times to 1.5GH/s. Thirty-one hours later, an investigation revealed that the attacker took away 580,000 Feathercoin through a double-spending attack on the exchange, at a current price of $63,800.
Description of the event: Bitcoin exchange Bitfloor suspended operations after the theft of $250,000. The founder Roman Shtylman explained in a post on the Bitcoin Forum that an attacker obtained an unencrypted backup of exchange wallet keys and used these keys to transfer "BitFloor on hand" Most of the coins he held," Shtilman later locked this part of the money at around 24,000 BTC.
Description of the event: Bitcoinica was hacked twice in 2012. Hackers stole a total of 61,000 BTC, leading to the bankruptcy of Bitcoinica.
Description of the event: The attacker has a lot of computing power to launch a 51% attack. The interesting thing about the Coiledcoin attack is that it is not economically driven, but purely political. Although this move has caused some protests in the community, it shows how vulnerable the SHA-256 cryptocurrency with low hashing power is to attack.