The National Payments Corporation of India (NPCI) today said its systems are "fully secure" and the cyber fraud of more than Rs 90 crore at Pune based Cosmos Bank happened due to a malware based attack on the lender's IT system.

Hackers managed to siphon off over Rs 90 crore through a malware attack on the server of the bank and cloning thousands of debit cards, Cosmos Bank chairman Milind Kale had said.

The fraudulent transactions were carried out on August 11 and August 13 and the malware attack by the hackers originated in Canada, he said.

In a release, NPCI said one of its network members has confirmed about a malware based attack on their system which has caused a fraud loss of over Rs 90 crore.

"NPCI wish to reiterate that our systems are fully secure and this particular issue has occurred within the Banks own IT environment," it said, adding that NPCI will continue to extend support to the affected bank in identifying the cause of the fraud.

Head Risk Management of NPCI Bharat Panchal said the malware based attack on bank's IT system has caused the fraud. "Under the attack, maximum transactions have been reported from outside India. We are monitoring the situation continuously," he said.

The bank has also registered an FIR at the Chatushringi police station in the city. A case was registered under sections 43, 65, 66(C) and 66 (D) of the Information Technology Act and relevant sections of the Indian Penal Code.

Kale had said that over the two days, hackers withdrew a total Rs 78 crore from various ATMs in 28 countries, including Canada, Hong Kong and a few ATMs in India, and another Rs 2.5 crore were taken out within India.

On August 13, hackers again transferred Rs 13.92 crore in a Hong Kong-based bank by using fraudulent transactions, he had said.

Kale had said the cooperative bank's core banking system was not affected and that it has already appointed a professional forensic agency to investigate the fraud.

As a precautionary measure, the bank has closed ATMs operations and suspended net and mobile banking facilities, he had said.