Ransomware attacks have risen over recent weeks, with Bitcoin emerging as one of the preferred payment methods for hackers. The payments have now run into millions of dollars.

Data acquired by cryptocurrency trading simulator Crypto Parrot indicates the amount of Bitcoin paid to major hacker groups has a value of more than $60 million. The Netwalker ransomware accounts for the highest payments at just under $28 million, followed by REvil at $11 million and Ryuk at $4.67 million. RagnarLocker ransomware accounts for $4.45 million to rank in the fourth spot, while DarkSide ranks fifth at $4.42 million.

Other notable Bitcoin ransomware payments include Egregor ($3 million), Conti ($2.5 million), Bitpaymer ($1 million), SynAck ($0.49 million) and Qlocker ($0.48 million)

Netwalker accounts for almost half of the payments at 46%, followed by REvil at 19%, and Ryuk accounts for the third-highest share at 8%. Qlocker has the least share at 0.79%.

"It is worth mentioning that the ransomware payments in Bitcoin could be higher because there is no comprehensive public data on the total number of ransomware payments,” the report stated. “In the absence of exact data, it is not clear to determine the actual impact of ransomware and its relation to cryptocurrencies."

The rise in Bitcoin as the preferred payment method for hackers is due to the cryptocurrency's anonymous nature. Criminals prefer Bitcoin because it is not easy to track beneficiaries of the asset.

Furthermore, other privacy-centered cryptocurrencies, like Monero, are also gaining popularity as the preferred method for payments by hackers. However, with limited cash-out options, Bitcoin remains the go-to crypto for hackers.