krebsonsecurity writes: "Merchant banks that process credit card payments for fake antivirus or "scareware" exhibit a distinctive pattern of card processing that could be used by Visa and MasterCard to weed out the rogue processors, according to a new study by the University of California, Santa Barbara. From the study: "The UCSB team found that the fake AV operations sought to maximize profits by altering their refunds according to the chargebacks reported against them, and by refunding just enough to remain below a payment processor’s chargeback limits. Whenever the rate of chargebacks increased, the miscreants would begin issuing more refunds. When the rate of chargebacks subsided, the miscreants would again withhold refunds." The study also highlights how few customers ever request a refund, and how affiliates pushing this junk software made more than $133 million."