It's not illegal. Card box promotion of credit card is an ordinary commodity promotion activity, which is not illegal. However, whoever uses a forged, invalid or fraudulent credit card of another person, maliciously overdraws (refers to the act that the cardholder overdraws beyond the prescribed limit or time limit for the purpose of illegal possession and fails to return it after being urged by the issuing bank), steals a credit card and uses it, shall be convicted and punished in accordance with the provisions of Article 264 of this Law.