DBS Group Holdings saw its stock price plummet by more than 3% during Tuesday's trading session, as investors reacted to news of a ransomware attack on one of the bank's vendors. The incident has potentially exposed sensitive information of thousands of DBS customers, raising concerns about data security and the bank's reputation.

According to reports, Toppan Next Tech (TNT), a data vendor responsible for printing customer statements and letters for DBS, fell victim to a ransomware attack. The breach has potentially compromised customer information of approximately 8,200 DBS clients, primarily affecting DBS Vickers accounts and some Cashline loan accounts. The potentially exposed data includes customers' names, postal addresses, and details related to equities held under DBS Vickers and Cashline loans.

While DBS has assured that its systems were not directly compromised and that customer deposits and monies remain safe, the incident has clearly shaken investor confidence. The bank stated that there is currently no evidence of unauthorized transactions resulting from the breach. However, the potential exposure of customer data poses significant reputational risks for DBS, which is Singapore's largest bank by market capitalization. The incident also highlights the vulnerabilities that can arise from third-party vendors handling sensitive financial information, potentially leading to increased scrutiny of banks' data management practices.