Peppers said he was informed of the fine in an email from the league on Wednesday night. The first-round pick said he stopped reading the letter when he saw the dollar amount.
Peppers delivered a hard blow to Malone's chest area in the fourth quarter, but the official ruled that he made contact with the receiver's helmet and assessed him a personal foul. Cincinnati scored a touchdown moments later to wrap up its 30-16 win.
Peppers feels he led with his shoulder and his hit was within the rules. He's still unclear as to why Malone was considered a "defenseless" receiver as he appeared to be running with the ball.
"I just feel like any kind of violent collision, they just flag," Peppers said. "As a DB, what do you want us to do? When you go low, you're a dirty player and the torque from the hit folds a receiver and his helmet comes down on your helmet, they still throw the flag. You can barely touch those guys when they're running their route. Now you can barely touch them when they're catching the ball."
Peppers plans to appeal the fine.
ESPN's Pat McManamon and The Associated Press contributed to this report.