Spammers have sent e-mails to users to use fake ‘unsubscribe’ spam emails to verify valid email accounts used for phishing scams and other malicious activities.
The “confirmation” emails, which use topics such as “Verification,” “Request, please confirm your subscription” and “We_need your confirmation asap” come in colorful boxes with links asking users if they want to sign in or unsubscribe.
After clicking on the subscribe/unsubscribe links, a new email is created by the user mail client, which is sent to many emails that are under the control of the spammer.
While users expect not to receive any more messages after they send the email, fraudsters do check to see if their email is valid.
Email users are advised to ignore when they receive an email asking them to subscribe/unsubscribe.
For more information, read the original story in Bleeping Computer.