Misandrists posing as feminists absolutely do exist. I actually lived with a few decades ago, back when women unfairly and even abusively criticizing men was considered more socially acceptable or even "cool" where I lived, and they were awful people. By definition, though, they're not actually feminists and are thankfully uncommon amongst anyone familiar with and practicing feminism. It's antithetical.

It's kind of like people who don't know much about socialism that tell everyone they're socialists because they are in favor of government safety nets. Many people don't actually know what socialism is (nor feminism, for that matter), so they don't know these people are full of shit when they make these claims.