The US Treasury has tracked $5.2bn worth of Bitcoin transactions likely to have been ransomware payments in the first half of 2021.
Its Financial Crimes Enforcement Network (FinCEN) bureau hinted in a new report that even this amount might only be the tip of the iceberg. It’s linked to the top 10 ransomware variants, but FinCEN said it identified 68 ransomware families in total.
The most frequently reported variants were REvil/Sodinokibi, Conti, DarkSide, Avaddon and Phobos.
The $5.2bn figure is associated with 177 wallet addresses mentioned in the suspicious activity reports (SARs) sent by banks to the authorities to combat financial crime and money laundering.
The number of those SARs related to ransomware has soared over the first half of 2021, FinCEN said.
Some 635 were filed during the reporting period of January 1 and June 30 2021, up 30% from the total of 487 SARs filed for the entire 2020 calendar year. There were 458 transactions reported in these SARs, and a total value of suspicious activity of $590m, which is more than the value reported for all of 2020 ($416m).