Clever hackers don't even need your password to access your account

Here we go again. 
Yahoo is warning some of its users that hackers may have used forged cookies — small files that websites create to store your information — to log into their accounts, thus gaining access without a password. 
Forging. Cookies. 
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The attack, which was originally announced in a security update in December 2016, took place between 2015 and 20