The term for the use of typographical symbols to replace curse words is grawlix. The term was coined by the cartoonist Mort Walker to describe a common trend in comic books.
Outside of comics, grawlix may be encountered on social media and used for humorous effect or to avoid excessive profanity in some book titles. It consists of a random string of punctuation such as at signs, exclamation points, question marks, and dollar signs (e.g., “#$%@!”).