Yahoo users who have received so-called email message alerts like the one below, which claim their mailbox service will be blocked, should not click on the link within them. This is because the email messages are phishing scams being sent by cybercriminals to their potential victims in an attempt to trick them into visiting a phishing website that steals email account usernames and passwords.
The "Yahoo Mail Box Service Will Be Blocked" Phishing Scam
From: Yahoo <naschristian@yahoo.com>
Sent: Tuesday, October 17, 2017, 7:03:54 AM GMT+3
Subject: Mail Box Service Will Be Blocked(FINAL WARNING)
YAHOO
Dear user,
Your Yahoo account has been marked for immediate shutdown due to non-verification.
Please follow the attachment below to verify and prevent loss of account.
This warning will expire in 24 hours!
Sincerely
Yahoo!
If the link in the phishing email message is clicked by the recipients, they will be taken to a phishing website and ask to sign-in. If they attempt to do so, their Yahoo account credentials (usernames and passwords) will be sent to the cybercriminals behind the scam. Once the cybercriminals have gotten the stolen credentials, they will gain access to the accounts, hijack them, and use them fraudulently.
Therefore, Yahoo users who have received email messages with a link to update their information or make changes to their accounts should always go directly to mail.yahoo.com and sign into their accounts instead of clicking on the link. Once Yahoo users have signed into their accounts, they will be noticed of changes or updates, if there are any. Going directly to mail.yahoo.com and signing in from there is only guaranteed way of preventing Yahoo users from becoming victims of phishing scams.
Yahoo users who have already been tricked by the phishing scam are asked change their passwords immediately before their accounts are hijacked and used fraudulently. If their accounts have already been hijacked by cybercriminals, they can click here for instructions to regain access to their accounts.