1. CoinDash ICO Hack
A hacker changed the address, causing donations worth $10 million to go to an unknown party.
2. Parity Wallet Bug
A bug was found in its multi-signature wallets, compromising several companies’ ICO fundraisers. Resulting in at least 150,000 ethers being stolen from user accounts. At the time, the ethers were worth roughly $30 million, but they're worth closer to $105 million as of mid-December.
3. Enigma Project Scam
Blockchain startup Enigma saw its website, mailing lists and an administrator account on its Slack channel compromised when fraudsters launched a fake token pre-sale in August, defrauding potential investors of more than 1,500 ethers.
4. Parity Wallet Freeze
A Parity user accidentally found a bug in the software code, freezing more than $275 million in ether.
5. Tether Token Hack
Tether claimed that roughly $31 million’ worth of tokens were taken from their virtual treasury and sent to an unknown bitcoin address.
6. Bitcoin Gold Scam
Shortly after the launch of a bitcoin fork called bitcoin gold, some bitcoin users had their cryptocurrency wallets drained after using a service seemingly endorsed by the project's #DevelopmentTeam , marketed as a way to authenticate whether a user was eligible for bitcoin gold funds, the website’s operators instead stole more than $3 million in bitcoin, bitcoin gold, ethereum and litecoin.
7. NiceHash Hack
NiceHash reported being hacked early in December, later confirming that about 4,700 in bitcoin was stolen. At the time, that was worth approximately $78 million.
8. EtherDelta DNS hijack
Late in December, an attack on Etherdelta DNS allowed hackers to redirect users into a fake website, which led to the theft of an unknown amount of Ethereum and ERC20 tokens.