"The court granted the application of the investigation to elect preventive measures in the form of remand in custody for Mikhail Golovachuk", the spokeswoman said, adding that the same was ruled with regards to Khansvyarov.
Khansvyarov and Golovachuk will be under arrest until March 13 on a charge of unlawful use of payment means, under a corresponding article of the Russian Criminal Code.
REvil is believed to be responsible for the ransomware attack on the software firm Kaseya in July, which impacted up to 1,500 businesses worldwide. The group has received more than $200 million in ransom payments, according to the Treasury Department.
The US previously offered up to $10 mln for information leading to the identification or location of any REvil leaders.