The worst suspicions were confirmed! I banned under paragraph 6 J
Using any unauthorized third party programs, including but not limited to "mods," "hacks," "cheats," "scripts," "bots," "trainers," and automation programs, that interact with the Software in any way, for any purpose, including, without limitation, any unauthorized third party programs that intercept, emulate, or redirect any communication between the Software and Riot Games and any unauthorized third party programs that collect information about the Game by reading areas of memory used by the Software to store information.
EDIT: No. I never used boosters or something else illegal.
They said, they can't give me more details on the use of vulnerability, because it would hurt their further investigations (sorry if my translation not a perfect).
It seems to me that they began to track the value of a variable and send report to the server, if it is greater than 2250
But maybe they decided that punto switcher (which I switch the keyboard layout) or AHK (with which I enter the password with a single keystroke) are cheating. It is difficult to say. Let's wait until banned someone else :/