The Treasury Department announced Wednesday that it had sanctioned two Bitcoin network addresses, a first of its kind action against accounts in a digital currency network, as well as two Iran-based men associated with the accounts for allegedly helping facilitate hacks involving ransomware.

The Treasury Department’s Office of Foreign Assets Control claimed the two men, Ali Khorashadizadeh and Mohammed Ghorbaniyan, aided in converting Bitcoin obtained through ransoms on computers and networks into Iran’s rial currency. Millions of dollars worth of Bitcoin flowed through the two addresses Treasury singled out, though not all of it may be derived from the hacks.