CoinEx is based out of Hong Kong, and was recently forced to stop serving US customers as part of a settlement with the New York Attorney General which also required them to pay a $1.7 million fine.
Stake acknowledged the attack on their Twitter account, writing that "We are investigating and will get the wallets up as soon as they're completely re-secured."
Stake is an Australia-based cryptocurrency casino and sports betting platform that has enjoyed endorsements from various celebrities, and which shelled out $100 million in 2022 for an endorsement deal with Drake.
On September 6, the FBI announced that they believed the Lazarus Group was behind the theft. Lazarus is a group of North Korean state-sponsored hackers allegedly responsible for crypto hacks totaling hundreds of millions of dollars.
After prominent Bitcoiner Jameson Lopp tweeted that the issue "look[s] more like a hack", CoinsPaid replied "Our team is aware of the issue... Please wait for the official announcement on this topic." Crypto researcher zachxbt responded, "The issue is you got hacked by North Korea that's what lol", referencing the increasing suspicion that the Lazarus group may be behind the disruption. Sure enough, CoinsPaid later confirmed that they had been hacked for $37.3 million, and announced that they suspected the Lazarus Group was behind it.
Some have been speculating that there are connections between this incident and the $60 million hack of the Alphapo crypto payments processor on July 22. Alphapo also provided services to various online casinos. Indeed, there seem to be connections between Alphapo and CoinsPaid, and they may in fact be operated by the same people.
Following the thefts, Atomic Wallet tweeted that they were aware of the reports of wallet compromises, and that they were attempting to learn more about the attacks, but had not yet confirmed any method of attack. They've since taken down the wallet software download page, likely out of concern that the software itself has been compromised.
Crypto sleuth zachxbt compiled a list of reported compromised Atomic Wallets, finding that multiple individuals lost multiple millions in the attack. The largest known individual theft so far involved almost $8 million in USDT (Tether); other individuals lost $2.8 million in USDT and 1,897 ETH (~$3.5 million).
Users of Atomic Wallet have been advised to transfer their assets to other wallets.
On June 6, both zachxbt and blockchain research group Elliptic speculated that the laundering strategy by the thieves resembled that of the North Korea-linked Lazarus Group, which has been responsible for other major crypto thefts.
Now, the FBI has accused two groups of North Korean hackers — Lazarus and APT38 — of perpetrating the Harmony hack. The groups then used Tornado Cash and RAILGUN to launder the funds.
Tornado Cash is the most prominent cryptocurrency tumbler (or "mixer") and has been used in a multitude of instances to launder proceeds from cryptocurrency hacks and scams. In a press release, the Treasury Department named the North Korea-sponsored Lazarus Group's $625 million hack of Axie Infinity in March, the $100 million theft from Horizon Bridge in June, and the $190 million hack of the Nomad bridge in August as contributing to the decision.
Although Tornado Cash had claimed to be complying with sanctions in the wake of the Axie hack, the Treasury Department wrote in their press release that, "Tornado Cash has repeatedly failed to impose effective controls designed to stop it from laundering funds for malicious cyber actors on a regular basis and without basic measures to address its risks".
Tornado Cash is also widely used to maintain privacy in a world where transactions are publicly visible, and it remains to be seen how the cryptocurrency ecosystem will react to this major development. Tornado Cash is also relatively decentralized in its operations, meaning it may be difficult for the sanctions list to be kept up to date and for the sanctions to be enforced.
The fallout from the sanction was swift: in the days following the action, Tornado's source code repository was removed from Github and the accounts of some of its developers were suspended; the project's Gitcoin funding page was taken down; and the project's own website, governance pages, and Discord server went offline.
- Specially Designated Nationals List Update, U.S. Department of the Treasury
- "U.S. Treasury Sanctions Notorious Virtual Currency Mixer Tornado Cash", U.S. Department of the Treasury
On June 23, someone was able to steal assets from the bridge that they then converted to more than 85,800 ETH. The stolen funds are notionally valued at almost $100 million, assuming the thief can cash them out successfully. Hours after the attack, most of the funds remained in the thief's wallet and had not yet been laundered.
A June 29 analysis by blockchain research firm Ellipsis claimed that "there are strong indications that North Korea's Lazarus Group may be responsible for this theft". Lazarus was also behind the $625 million bridge hack in March, targeting the Axie Infinity game.
The U.S. began sanctioning various wallet addresses belonging to the hackers in mid-April, though have faced obstacles given that it is trivial for the hackers to create new wallets. The use of cryptocurrency tumblers (also called "mixers") has also stymied the government's attempts to limit the DPRK's access to the ill-gotten funds. Blender is not the primary tumbler that Lazarus has been using — that would be Tornado Cash, which they have used to tumble more than $213 million from the hack. Tornado has taken perfunctory steps to comply with sanctions, but nothing that would meaningfully impact Lazarus' ability to use the service.
- "U.S. Treasury Issues First-Ever Sanctions on a Virtual Currency Mixer, Targets DPRK Cyber Threats", U.S. Department of the Treasury
Sky Mavis announced that they had halted the Ronin Bridge and Katana DEX, and were making changes to their network to try to guard against future attacks. They also wrote that they were "working with law enforcement officials, forensic cryptographers, and our investors to make sure all funds are recovered or reimbursed".