The Blockchain Group is behind a number of different services, including a crypto wallet called Eniblock and an open source software bounty project called Bountysource. Users of the Bountysource project have been complaining about issues receiving payments since as far back as May 2023.
According to researcher zachxbt, who himself was one of the impersonated, the scammers have stolen more than $300,000 in various assets using this technique.
This is not the first time such a technique has been used — a scammer attempted a similar, though less successful, scheme in April 2022. Scams like this take advantage of the poor UX in the crypto world for tracking and revoking wallet permissions that have been granted, requiring people to use third-party websites created for this purpose. Some of them are legitimate, but there are many malicious copies of these revocation sites that prey upon users who may be acting quickly in fear that their assets are at risk.
Unciphered worked with various wallet providers to contact people whose wallets may be vulnerable, though ultimately it is up to those wallet holders to secure their funds by creating new wallets and transferring their tokens. Unciphered also noted that some Dogecoin, Litecoin, and Zcash wallets may be vulnerable due to shared code.
CREATE2to generate new addresses for each malicious signature. This allows the drainer to sidestep security alerts built into some crypto wallet software that would flag known malicious addresses.
ScamSniffer identified one victim who lost almost 17,000 GMX (~$927,000) to this drainer after signing a malicious transaction.
Crypto researcher zachxbt observed that the wallet targeted for the theft had in 2019 received a transfer from the Binance deployer, suggesting that the compromised wallet may have some ties to Binance itself.
The attacker then went to convert the R into ETH, which they would then be able to launder and cash out. However, an error in the attacker's code caused 1,570 ETH ($3.25 million) to be sent to the burn address, rendering it permanently inaccessible to everyone including the hacker. Only 7 ETH remained. However, because they had to spend ETH to fund the attack, the hack ultimately resulted in a loss of 4 ETH (~$8,000) for the perpetrator. Oops.
As a result of the hack, the R stablecoin lost its dollar peg, plummeting down to around $0.70. Raft acknowledged the attack and announced that they had paused minting.
Poloniex was initially tight-lipped, posting on Twitter that they had "disabled for maintenance" an exchange wallet. Justin Sun later updated that they were investigating the "hack incident", and promised to "fully reimburse" the massive theft... somehow. He later tweeted that they would offer a 5% "bounty" to the hacker if they returned the funds within a week, threatening to "engage law enforcement" otherwise.