Russian spies

Though there's no solid evidence yet available, an article published by WSJ claims that the Russian state-sponsored hackers stole highly classified NSA documents from a contractor in 2015 with the help of a security program made by Russia-based security firm Kaspersky Lab.

Currently, there is no way to independently confirm if the claims on the popular security vendor published by the Wall Street Journal is accurate—and the story does not even prove the involvement of Kaspersky.

The hack, which the DOJ said was initiated in January 2014, affected at least 500 million Yahoo accounts. Some of the stolen information was used to "obtain unauthorized access to the contents of accounts at Yahoo, Google and other webmail providers, including accounts of Russian journalists, US and Russian government officials and private-sector employees of financial, transportation and other companies," the DOJ said in a statement.