China has reemerged as the second-largest locale despite a government ban on the activity last year.

Following the mining ban in China last year, the country has seen a sudden surge in activity through “covert mining operations” and has “re-emerged as a major mining hub” grabbing 21.11% of global hashrate.

“This strongly suggests that significant underground mining activity has formed in the country, which empirically confirms what industry insiders have long been assuming,”

It seems covert mining is still happening in China through routed through virtual private networks that make it appear the computers are operating in another country.

CCAF’s methodology, which is based on aggregating geolocation data given by partner mining pools, is prone to errors as many miners miners might hide their identity using proxy services like VPNs.

Kazakhstan was third at 13.22%, followed by Canada taking 6.48% of global hashrate. Russia accounted for 4.66%, and has seen cryptocurrency mining operations relegated elsewhere, said the report.