The angriest reaction came from Raj Samani, the chief scientist and Fellow at US firm McAfee, who said that as a regular Uber customer, the news made him incredibly angry.

"Uber has treated its customers with a complete lack of respect," Samani said. "Millions of people will now be worrying over what has happened to their personal data over the past 12 months, and Uber is directly responsible for this.

"In opting to not only cover up the breach, but actually pay the hackers, Uber has directly contributed to the growth of cyber crime and the company needs to be held accountable for this.”

McAfee vice-president Vincent Weafer said bribing hackers to keep quiet about a data theft was not a common tactic.

"It’s likely under-reported as organisations aren't going to tell the world that they're doing it," he opined.

"But, if we look at ransomware, a more common example of people paying criminals to decrypt their data, we know from multiple research reports that there's a high percentage of cases where paying does not result in data being restored correctly. You're essentially relying on the integrity of criminals, and the wisdom or value of that is obviously debatable."

He likened the Uber breach to those that have taken place at Yahoo! and Equifax. "This is yet another example of a fairly significant data breach, following on the heels of similar breaches at Yahoo and Equifax."

Weafer said it was not certain whether the data was still in the wild and exploitable or whether Uber had been effective in mitigating the risk by paying the hackers.

"This is a good example of why organisations need to be very careful of how credentials are used and managed. We know attackers have been trying to track down administrator credentials — the keys to the kingdom — that allow them to move around within an organisation with ease," he said.

"Keeping those credentials separate and different for various repositories, as well as managing them in a secure manner should be treated as a core principal of security info management."

Webroot threat research director David Kennerley said given the current climate around data security and breaches it was astonishing that Uber paid off the hackers and kept this breach under wraps for a year.

"The fact is there is absolutely no guarantee the hackers didn't create multiple copies of the stolen data for future extortion or to sell on further down the line. A security breach of this size will potentially damage any business’ reputation, but how a company behaves following a breach is vital," he said.

"Potential victims deserve to be informed as soon as possible, so they can better protect themselves going forward - from changing passwords, and being aware they are now prime phishing targets. Being open and transparent and keeping customers informed is key, you can’t simply sweep these things under the carpet."

Udi Mokady, the chairman and chief executive of Israel-based security company CyberArk, said the Uber breach put the spotlight on the critical security vulnerabilities created by privileged credentials that are often left unmanaged and unprotected – "especially at companies that are using DevOps and the cloud to bring new applications to market at high velocity".

"Analyst firm Forrester estimates that 80% of security breaches involve privileged credentials. Despite this, according to a recent CyberArk survey, 75% of organisations report no strategy to manage and secure DevOps secrets, with 99% of respondents failing to identify all places where privileged accounts or secrets exist," he said.

Mokady said this lack of visibility and control created a massive opportunity for attackers. "It also underscores the need for secrets management solutions," he added.