Yahoo users, if you have received the "Your Mail-Box Has Reached an Upgrade Stage" email message below, which claims your account will be locked, please delete the same it and do not follow the instructions in it. This is because the email is a phishing scam being sent by cybercriminals to trick Yahoo users into clicking on the link in them, which goes to phishing websites that steal Yahoo usernames and passwords.
The "Yahoo Your Mail-Box Has Reached an Upgrade Stage" Email Scam
From: Yahoo mail <markhamilton98643@yahoo.com>
Date: October 15, 2019 at 9:59:25 PM GMT+8
Subject: Your Mail-Box has reached an upgrade stage.(FINAL WARNING)
YAHOO MAIL
Dear Customer
This is to notify you for the final time that your account is not yet upgraded after several warnings
Since you have refused to upgrade your account and we might be forced to lock up your account if this noticed is ignored.
Please follow the steps below for your upgrade process.
UPGRADE MAILBOX
Please do not ignore this email to avoid your account closure
Regards
Yahoo!!
Yahoo users should never click on a link to sign into their accounts; they should instead, go directly to mail.yahoo.com or yahoo.com and sign-in from there. Once they are signed in, they will be alerted to updates, changes or other important notifications. Going directly to Yahoo’s website to sign into their accounts, will protect Yahoo users from phishing links that go to fake websites that steal usernames and passwords. Phishing websites steal their visitors’ usernames and passwords by asking them to sign into their accounts on the same fake website. Once visitors to the websites attempt to sign-in, their usernames and passwords (credentials) will be sent to the cybercriminals responsible for the phishing websites. As soon as the cyber criminals receive their potential victims’ usernames and passwords, they will sign into their accounts, hijack and use them fraudulently.
Yahoo users who have been tricked by the "Update to Yahoo Mail 7.1" or "Yahoo Warning Mailbox Limited" email scam, are asked to change their Yahoo passwords immediately before their accounts are hijacked and used fraudulently.