Cybersecurity incident — 2017-02-15 00:00:00
Affected organization: Yahoo!
Affected country: United States of America
Industry: Information
Event type: Exploitive
Event subtype: Exploitation of Application Server
Motive: Political-Espionage
Actor: Undetermined
Actor type: Criminal
Actor country: Undetermined

Yahoo sends out another round of notifications to users, warning some that their accounts may have been breached as recently as last year. The accounts were affected by a flaw in Yahoo's mail service that allowed an attacker, most likely a "state actor", according to Yahoo, to use a forged cookie created by software stolen from within Yahoo's internal systems to gain access accounts without a password.