A computer-implemented method for detecting potentially compromised payment cards is provided. The method uses a processor in communication with a memory. The method includes storing a plurality of tokens. Each token includes merchant identification data corresponding to a first merchant. The method also includes transmitting the plurality of tokens to the first merchant and receiving an authorization request message from a merchant. The authorization request message includes a token and a merchant identifier corresponding to the merchant. The method further includes determining that the received token is one of the plurality of tokens associated with the first merchant, determining that the merchant identifier does not correspond to the first merchant, transmitting a message including instructions to decline the transaction, and attaching a potentially compromised flag to the first merchant. The potentially compromised flag indicates a heightened probability of fraudulent activity.