The Swift bank logo is pictured in this photo illustration taken April 26, 2016.
The Swift bank logo is pictured in this photo illustration taken April 26, 2016.

A global financial network used by 11,000 banks to transfer billions of dollars daily has issued an urgent warning to customers to install a software upgrade after discovering "a number of recent cyber incidents."

The warning from SWIFT, a global messaging network that sends payment instructions, comes as law enforcement officials in Bangladesh and elsewhere investigate February's theft of $81 billion from the Bangladesh central bank.

It is the first time SWIFT has acknowledged the Bangladesh Bank cyber attack was not isolated, but one of several recent attempts to hack the company's messaging platform.

Victims or the value of the previously undisclosed attacks were not disclosed by SWIFT.

To combat the attacks, SWIFT released a security update to the software that banks use to access its network.

The company hopes this will thwart malware that British defense contractor BAE Systems said was likely used by hackers in the Bangladesh Bank robbery.

In a notice to customers Monday the company said, "SWIFT is aware of a number of recent cyber incidents in which malicious insiders or external attackers have managed to submit SWIFT messages from financial institutions ... to the SWIFT network."

Because SWIFT is a key player in international financial transactions, central banks throughout the world have reason to be concerned. "These hacks specifically target financial institutions," said Shane Shook, a consultant who investigates large financial crimes. "It is much more efficient than stealing from consumers," he added.

Some material for this report came from Reuters.