Yahoo hacked by ‘professional’ criminals seeking to sell data: researchers

WASHINGTON — The massive theft of Yahoo user data disclosed last week came from “professional” hackers seeking to profit from the breach, according to an analysis by security researchers.

The analysis published on Wednesday (Sept 28) by the security firm InfoArmor, which claims to have seen some of the data, contrasts with Yahoo’s claim that the attack was likely “state-sponsored”, but did suggest that stolen data was sold to a state-sponsored group at one point.

“Yahoo was compromised in 2014 by a group of professional blackhats (hackers) who were hired to compromise customer databases from a variety of different targeted organisations,” the report said.

The researchers said the first mention of Yahoo data for sale on “dark” online markets occurred in April 2016.

They added that the vast majority of the data “is not legitimate”, and includes invalid, deleted and nonexistent accounts but that the attackers “misrepresented this data set in order to sensationalise and sell it for the purpose of monetising” the data.

The hackers sold the data to “a state-sponsored party who had interest in exclusive database acquisition” and also to “cybercriminals who planned to use the data for spam campaigns against global targets”.

The hack occurred in late 2014 affecting some 500 million users worldwide, according to Yahoo’s disclosure last week.

It was not immediately clear if the disclosure would affect the sale of Yahoo’s core business to telecom group Verizon for US$4.8 billion (S$6.5 billion). AFP