Four years ago web giant, Yahoo, was hacked leaving user details exposed to malicious third parties. While it was originally reported that around a billion people were impacted by the attack, the firm has now admitted that the true figure is much higher.

The Guardian reports that a total of over three billion accounts were compromised by cybercriminals in 2013, representing every single Yahoo user at the time.

Ongoing investigations have revealed the true extent of the hack and Yahoo said that it will be getting in touch with those who have been affected.

The good news is that no payment card information or other financial data was stolen as part of this breach. Yahoo has also taken steps to shore up its security across the board and prevent similar attacks succeeding in future.

A number of lawsuits against Yahoo are still pending and the regulatory fines are mounting up, so it could be that this news gives critics even more ammunition to use against the embattled organisation.

Providing a range of digital services in countries around the world, the fact that Yahoo suffered a hack of this scale is perhaps unsurprising given the potential prize that criminals could claim. For people wanting to carry out safe shopping online, the importance of security was made clear when the news of the attack broke.

Because of the number of accounts now known to have been compromised in this breach, the need to regularly update passwords to avoid being caught out in future should be apparent to all web users. This is relevant for anyone using social media, sites that offer safe shopping online and every other internet-enabled service, since if one firm is hit by a successful attack then the stolen data can be used to hack other accounts.