Nicholas@
Сомневаюсь, что такая функция есть, но переведу на английский обязательно.

Filip Havlicek
User Nicholas@ would like to know if avast! Mobile Security can block any SMS message depending on the text in its title and body. For example, he doesn’t want to receive messages with the word “taxi” in the title or body. So he’d like to fill this word somewhere in his avast! Mobile Security in order to block such messages.