Yahoo users who have received email messages like the one below, asking them to upgrade their accounts or else they will lose them, are asked to delete the same email messages. This is because the emails are phishing scams being sent by cybercriminals to trick Yahoo users into visiting a fake website that will steal their account usernames and passwords.
The "Yahoo Classic Email Upgrade to Newest Version" Phishing Scam
Subject: Newest version of your email
Date: On Thursday, November 2, 2017, 3:57 PM,
From: Yahoo! <notify-alerts@cc.yahoo-inc.com>
AT&T Yahoo
Dear,
The Classic version of your Mail will be replaced by our new version on 3rd November 2017. So it's time to upgrade, before you lose your email access.
Log-in Restore
Protecting your information is important to us and we work continuously to strengthen our defenses against the threats targeting our Financial Institution.
Thanks for choosing Yahoo! Inc.®
Remember, never click on a link to sign into your Yahoo account, always go directly to https://mail.yahoo.com and sign-in from there instead. Once you have signed in, you will be notified of an upgrade or important changes if there are any.
For Yahoo users who have already been tricked, they may attempt to change their passwords immediately before their accounts are hijacked and used fraudulently. If their accounts have already been hijacked, they may click here for help regaining access to them.