Debit cards
Representational Image of debit cards.Pixabay

India's finance ministry on Thursday said that the customer's debit cards are "completely safe" and there was no need to panic following the security breach, which left 3.2 million (32 lakh) debit cards affected by the malware.

"Only about 0.5 percent of the debit card details were compromised, while remaining 99.5 percent cards are completely safe and bank customers should not panic," G C Murmu, Department of Financial Services Additional Secretary was quoted as saying by the Press Trust of India.

It is believed that the financial data compromise took place from specific machines during a particular period of time, which is a limited issue and the banks have asked their customers to replace their debit cards or change the PIN number, Murmu added.

The extent of financial loss resulting from the security breach is reportedly being assessed.

Also read: Indian banks to re-issue 3.2 million debit cards following security breach

Financial data of users who had done transactions from Hitachi ATM machines were compromised during the month of May, June and July, Murmu told the agency. The National Payments Corporation of India (NPCI) said the problem was detected after some banks complained that their customer cards were being fraudulently being used in the US and China, while the customers were in India.

NPCI is working closely with all the stakeholders and once the root cause is identified (post the forensic investigation), it would issue a set of recommendations as precautionary measures to member banks, PTI added.

In what is said to be the biggest card replacement exercise in the Indian banking sector, banks assured their customers that the debit cards will be issued replaced or re-issued. The worst-hit banks are State Bank of India (SBI), HDFC Bank, ICICI Bank, YES Bank and Axis Bank.

In a statement, HDFC has said it has taken action in the matter. "Besides advising those customers who we know have used a non-HDFC Bank ATM in the recent past to change (their) ATM PIN, we are advising our customers to use only HDFC Bank ATMs as we believe security controls at some of the other bank ATMs may not be at par with HDFC Bank ATMs."

SBI, along with its subsidiary banks, blocked 6.52 lakh debit cards of its customers following a suspicious malware-related security breach in the ATM network. It has said that it would re-issue the debit cards to its customers.