Apple’s mobile payment system Apple Pay has been hit by a wave of fraudulent transactions using stolen credit-card data from a spate of breaches at retailers, the Wall Street Journal reported, citing people familiar with the matter. The transactions stemmed from breaches at retail giants including Home Depot Inc and Target Corp, the Journal reported on Thursday. The majority of unauthorized purchases have been for big-ticket items bought with smartphones at Apple’s own stores, the Journal said. Apple Pay lets iPhone 6 and iPhone 6 Plus users make purchases with participating apps and in-store purchases using near-field communication technology. Apple Pay had over 1 million activations in the first three days after it became available. At the earnings call, Apple chief Tim Cook looked rather chuffed with Apple Pay’s reception. He claimed that Apple Pay has received over a million activations within 72 hours of being made available to iOS devices. At the same time, he expressed his displeasure at the fact that some retailers were blocking the service to evade transaction fees to credit card companies. With inputs from Reuters