Capcom made a statement on social media to announce how they are aware to the people modding in their own high rank quests with unique awards to cheat, and are planning to release “additional countermeasures in future updates to detect users who have engaged in unauthorized modification.”
Announced on social media, but further elaborated on its website, the Monster Hunter developer has become more aware to the use of unsanctioned mods. Capcom seem highly against the use of these mods, with demands that if you are to join a game and believe to be playing in a modified lobby you should leave and “stop playing immediately” alongside quitting the game without saving. It also warns to do this not only because it feels it to interferes with usual gameplay but also because it can “render the game unplayable.”
For the time being, Capcom is requesting the community to not join these missions as not much preventative is currently in the game. However, to help spot these modified high ranks quests they posted this image alongside its post.

Cheating in Monster Hunter has been an issue for a while within the community. And although most of the community inhabit this “out of sight” mentality towards it, the release of public leaderboards for the arena earlier this month with TU1 has caused for more concern from both the community and developers. Capcom has, however, also made compromises for the leaderboard, changing the rewards and making them easier to get despite the cheated current record holders because they want “to provide all hunters a reasonable and fair opportunity to obtain the event rewards.”
As of right now there isn’t a countermeasure and so players will just have to use their usual noggins and keep an eye out for any suspicious quests.