Yahoo! email accounts were hacked in 2014 by cybercriminals rather than a state-sponsored party as the web portal claimed, a security expert has said. Andrew Komarov, chief intelligence officer with security company InfoArmor, said so-called “hackers for hire” using pseudonyms well known in the underground community broke into the email provider’s data. Yahoo Inc said last week the attacker was a “state-sponsored actor” and that information stolen from at least 500 million users may have included names, e-mail addresses, phone numbers and even the answers to unencrypted security questions. In a report released on Wednesday, Arizona-based InfoArmor said: “Yahoo! was compromised in 2014 by a group of professional blackhats who were hired to compromise customer databases from a variety of different targeted organisations,” “The Yahoo! data leak, as well as the other notable exposures, opens the door to significant opportunities for cyber-espionage and targeted attacks to occur.”