The Monetary Authority of Singapore is investigating a ransomware attack on Toppan Next Tech, a vendor responsible for printing customer statements for DBS Bank and Bank of China (BoC) in Singapore, which exposed the personal data of thousands of customers.
DBS says it was alerted to the breach on 5 April. Preliminary investigations indicate that customer statements/letters of about 8,200 DBS customers have been potentially compromised.
Customer data that could have been compromised include first and last name, postal address, as well as details relating to equities held under DBS Vickers and Cashline loans.
DBS sends customer statements/letters to TNT for printing in encrypted files. As investigations are still ongoing, it is not known if the threat actor was able to decrypt the files.
DBS says the statements/ letters do not contain login credentials, passwords, NRIC details, deposit balances or total wealth holdings.
The bank says it has halted all printing jobs with TNT and is undertaking heightened surveillance to monitor any suspicious or unusual account activity to better protect impacted customers.
At Bank of China up to 3000 customers have been impacted by the attack.
The Cyber Security Agency of Singapore (CSA) is aiding TNT in its investigations and is advising on containment measures. Singapore's central bank says it is in close engagement with the affected banks on their risk mitigating measures and follow-up with customers.