A well-connected Russian hacker once described as “an asset of supreme importance” to Moscow was sentenced on Friday to nine years in a U.S. prison after pleading guilty to running a site that sold stolen payment card data, and to administering a highly secretive crime forum that counted...

Aleksei Burkov, an ultra-connected Russian hacker once described as “an asset of supreme importance” to Moscow, has pleaded guilty in a U.S. court to running a site that sold stolen payment card data and to administering a highly secretive crime forum that counted among its members some ...