Most of the banks are keeping their ATM (automated teller machine) booth operation suspended for 6-8 hours at night following a hacking alert issued by the Bangladesh Bank in late August.
Banking insiders said the measures may continue as the sector still faces a hacking risk. Some banks have formally notified their clients while some have not, putting their clients in a dilemma.
Sources said some banks keep their ATM booths closed for eight hours from 11:00pm to 7:00am while some keep it suspended for six hours from 12:00am to avert any fraud.
According to official sources, the Bangladesh Bank alerted all commercial banks in a circular on August 27 about a possible threat of hacking in the banking transactions through ATM booth, credit cards and other modes of online banking.
"The alert was issued following global media reports that a North Korean hacker group is trying to hack different banks in various countries," said a Bangladesh Bank official.
Ekram Kabir, executive vice president (communications) of Brac Bank, said his bank keeps the ATM booth transactions suspended from 12:00am to 6:00am following the central bank's alert.
He said every debit card holder of the bank was notified about the move.
Brac Bank's cyber security team has remained engaged to track and monitor round the clock.
"The situation suggests limiting ATM operation at night may be extended for few more days," he told UNB.
Customers in dilemma
Echoing Ekram Kabir, some officials of other banks also said they may continue suspension of ATM booth transactions at night as cyber-attack risk persists.
Due to the closing of ATM operation, many clients have to suffer as they cannot withdraw money to meet their needs.
"Suddenly I needed money for an emergency payment but I could not make the payment as it was not possible to cash out from ATM at midnight," said Kamrul Huda, a client of a commercial bank.
Bangladesh Bank officials said a North Korean hacker group named "Beagle Boys" is trying to steal money from various banks around the world through ATM booths and fake transactions.
Cyber-attack in banks is not new for Bangladesh as hackers had stolen $101 million from Bangladesh Bank account at the Federal Reserve Bank of New York in February 2016.
Of this, $81 million was taken away by the hackers through Philippines RCBC Bank while $20 million was blocked in Sri Lanka.
So far $15 million was recovered by the central bank while legal process is being pursued to recover the rest.
Bangladesh Bank filed a lawsuit against the RCBC at a New York court and the case remains pending.