Most of the dangerous destructive malware comes from Asian countries including Russia, China, Korea, Ukraine, etc. but most are only spread locally. Usually only distributed to businesses.
However ever country has a hand in spreading malware, in numbers the USA has more malware distributed globally to home users but most are just fake antivirus and other rogueware which are not destructive.
Fake antivirus and rogue security products are the most successful form of malware that I have ever seen. It doesn't need to use vulnerabilities or any advanced method to download and install. Just tricks users into believing they need to manually download and install it to fix their system. The users do all of the necessary work for them and infect their own systems.
Some users will even disable their AV to allow the rogueware to run.
Still there is a large number of malware from a unknown region.
Thanks.