The US has charged a Russian man with being behind a major cybercrime operation that affected individuals and businesses worldwide.Evgeniy Bogachev, said to be known as "lucky12345" and "slavik", is accused of being involved in attacks on more than a million computers.
The charges came as authorities seized control of a botnet used to steal personal and financial data.
Computer users were urged to run checks to protect themselves from the threat.
In a press conference held on Monday, the US Department of Justice said it believed Mr Bogachev was last known to be residing in Anapa, Russia.
Cooperation with Russian authorities had been "productive", a spokesman added.
In a entry added to the FBI's Cyber Most Wanted list, it stated: "He is known to enjoy boating and may travel to locations along the Black Sea in his boat."
His charges, filed in a court in Pittsburgh, included conspiracy, wire, bank and computer fraud, and money laundering.
The UK's National Crime Agency (NCA) said people probably had "two weeks" before the criminals would get the botnet functioning again, and posted advice on how to best protect computers.
Internet service providers (ISPs) will be contacting customers known to have been affected by either letter or email. The first notices were sent out on Monday, the BBC understands.