Malvertising group based out of Hong Kong behind Windows 10 apps and Microsoft games ads. Malvertising is behind millions of ads that redirect users to scams, malware, and adware bundles. Advertisers were creating corporate identities to partner with DSPs (demand-side platforms) It would then distribute their low quality and often malicious ads to other ad networks and publishers. This group has been very successful, with over 100 million ads shown in 2019 alone and their two biggest peaks were in May 2019 and June 2019.
Source: https://www.bleepingcomputer.com/news/security/group-behind-windows-10-app-malvertising-pushed-100m-ads-in-2019/