Yahoo, one of the biggest tech companies in the world, previously revealed that it discovered a security breach --- which affected at least 500 million users not more than three months ago. Now, the company has revealed that it discovered a 3-year old security breach --- compromising more than 1 billion of its user accounts.

The recent security breach announcement broke all previous hacking records, making it one of the biggest security breaches in history today. The company revealed just this week that the hack itself had occurred back in August of 2013. Yahoo did not specify whether both of these breaches were caused by the same hackers, but it did mention about suspicions of an unidentified foreign government being responsible for it. Despite this the company admitted that it still wasn't able to fully identify the source of intrusion and that it was still trying to figure out how it happened.

The hackers were apparently able to access a large amount of data from the company's servers --- including names, e-mail addresses, birth dates, phone numbers, and security question answers. However, Yahoo reassured its users that bank and credit card information were not compromised. Given the attack discovery, the company has started to prompt its users to immediately change their passwords and invalidate their current security questions and answers.

While Yahoo had reassured its users that the passwords hacked were scrambled twice, by encryption and by hashing, there is still the danger that users might have used the same passwords for their other online accounts. According to experts, the attack was most likely targeting specific information on specific individuals and likely conducted by a large organization or perhaps a foreign government. There hasn't been any large amounts of data posted online, which means that the attack probably wasn't done by one individual seeking to gain profit.