The incident occurred at the SBM Nariman Point Branch according to the bank's complaint with the Mumbai Police Economic Offences Wing (EOW) last week.
The EOW and the Cyber Cell experts are investigating the case and trying to ascertain if it is a malware attack, besides the SBM's own internal probe to find out the involvement of an insider.
On October 2, the SBM had said in a statement that its India operations had been hit by a cyber fraud with a potential loss of around $14 million.
However, it assured that no loss has been caused to any customer and that the SBM enjoyed sufficient liquidity for all its future plans.
SBM India, a subsidiary of SBM Holdings, has branches in Mumbai, Chennai, Hyderabad and Ramachandrapuram in Andhra Pradesh.
This is the second major cyber attack on a bank in Maharashtra in the past couple of months.
In two separate cyber-attacks on August 9 and 11, the Cosmos Bank Pvt Ltd, Pune, lost a total of Rs 94.24 crore to an international group of operatives working in tandem in several countries worldwide.
(With inputs from agencies.)