This is automatic message:
Your account has been banned because we detected that you used illegal softwares in your Games
You got reported by many players and we has to limit your account, our decision took 2 months, we analyzed all your activity and reports.

When the software detects a cheat on a player's system, it will ban them in the future, possibly days or weeks after the original detection. It may kick players from the game if it detects errors in their system's memory or hardware. No information such as date of detection or type of cheat detected is disclosed to the player. After the player is notified, access to online "Vac protected" servers of the game the player cheated in is permanently revoked and additional restrictions are applied to the player's Steam account.

The decision is permanent and it can't be undone.

Your account will get banned at 30, Apr 2020 (12:43:00) GMT
You will not be able to play on public servers in Dota2 and you will not be able to trade any in-game items after 30, Apr 2020 (12:43:00) GMT. They will be trade banned forever.