Who are the Russian cyber gang Qilin?

Russian cyber group, Qilin, is believed to have carried out a ransomware attack on Synnovis, a pathology services provider for major London hospitals. The attack led to cancellations of operations and tests and interference with blood transfusions. Qilin, a dark web-operating organisation with a two-year attack history, is also alleged to have targeted Big Issue Group and Yanfeng Automotive Interiors amongst others.