US technology giant Yahoo Inc is warning its users of potentially malicious activity taking place on their account between 2015-2016.
According to the latest internet company's investigation of mega-breach has exposed around 1 billion users' data several years ago in the development.
Although the development does not how many users were exactly affected by the malicious activity, which involved the use of forged cookies-- strings of data which can be used to allow people to access online accounts without re-entering their passwords.
Yahoo said in a statement issued in which it said that its investigation "has identified user accounts for which we believe forged cookies were taken or used. Yahoo is in the process of notifying all potentially affected account holders." The company declined to say how many people were potentially affected.
(With PTI Inputs)