The U.S. Treasury’s Office of Foreign Assets Control on Thursday re-designated Russian cryptocurrency exchange Garantex and added its successor platform Grinex to the sanctions list, accusing both of processing more than $100 million in transactions for ransomware gangs and other cybercriminals since 2019. The action freezes any U.S.-linked assets and bars Americans from dealing with the exchanges. Officials said Garantex shifted customer deposits to Grinex after law-enforcement agents seized its website in March. The two platforms allegedly laundered funds through the ruble-backed A7A5 stablecoin, which blockchain-analytics firm Elliptic estimates handles about $1 billion a day. OFAC simultaneously blacklisted A7 LLC, Old Vector LLC and other Kyrgyzstan-based entities tied to the token, as well as payments service Exved and Indefi Smartbank. The U.S. State Department offered a $5 million reward for information leading to the arrest of Grinex co-founder Aleksandr Mira Serda. The designations underscore Washington’s growing focus on stablecoins and regional intermediaries that facilitate sanctions evasion for Russian businesses following the invasion of Ukraine. Treasury officials warned that virtual-asset service providers worldwide must adopt robust controls or risk exclusion from the U.S. financial system. Parallel enforcement actions highlight broader pressure on crypto-related crime. Chainalysis and Canadian and U.S. agencies said their Project Atlas and related operations have frozen or prevented more than $74 million in scam proceeds, part of initiatives that have locked up over $300 million in illicit digital assets since late 2024. Separately, the Justice Department unsealed warrants to seize $2.8 million in cryptocurrency and other assets from alleged Zeppelin ransomware operator Ianis Aleksandrovich Antropenko.