I had nothing to do these eve, so I've collected data via codeforces api from the last three contests where was an enormous number of cheating attempts. With total number of approximately 4000 skipped submissions on problem A in these contests, the distribution of the cheaters that specified their countries is the following: 
Assuming that those 3000 people that didn't specified their countries are distributed uniformly among the countries, the cheating leader is Japan, not India (though, it is very close to Japan and has the second place). Countries that are not depicted have $$$\le 10$$$ cheaters.
But still I think that most "anonymous" users are from India.
You should consider that there are 2750 users from Japan on CF which makes 1.02 percent of it to be 28 users while 71844 users are from India which makes 0.91 percent of it to be 653. Now we have that 653 cheaters are from India and 28 from Japan which change everything. It can be also applied to another countries, which could change the graph. So, I think it would be better to make distribution considering number of people and not percent.
Not every user who sets their country as Japan is from Japan. Due to the global popularity of Japanese pop culture (e.g. anime, games) there are a lot of weebs/otakus who set their country as Japan although they come from countries from all over the world.
What's next, you're going to claim that Antarctica has the most cheaters?
Yep, Japanese People cheats the most, that's why we always see Atcoder Contests' solutions are getting leaked. They even livestream their solutions on YouTube and often speak Japanese in between the livestream (to confirm that they are really Japanese People). Moreover, Japanese People are so much concerned about cheating that, their country's best judge has a special feature of identifying cheater and tagging them as Cheaters in their profile. Moreover, Japanese People only cheats to pass their Job Interview and getting a job as getting a job in Japan is very hard because of their high population. I really feel pity that, Japanese People are really so bad!
Bro doesn't remember the KLU mass cheating incident
Change my mind, but cheaters should be executed!!
or lose all social credits in real life