Researchers at MailGuard have observed a phishing campaign that’s using phony “spam notification” emails that purport to come from Microsoft Office 365. The emails tell recipients that an important-looking email has been sent to their spam folder, and they’ll need to click a link to view the supposed message.

“Scammers are sending the email from ‘quarantine[at]messaging[dot]microsoft[dot]com’, and the display name is the recipient’s domain, to feign authenticity,” the researchers write. “The email subject is ‘Spam Notification: 1 New Messages’, alluding to the body of the email that informs the recipient that a spam message has been blocked and is being held in quarantine for them to review. Details of the ‘Prevented spam message’ are provided, with scammers personalizing the subject heading as ‘[company domain] Adjustment: Transaction Expenses Q3 UPDATE’ to create a sense of urgency and using a finance-related message.”

If a user clicks the link, they’ll be taken to a spoofed Office 365 login page. MailGuard notes that once an attacker compromises your Office 365 account, they can access a wealth of sensitive data.

“Providing your Microsoft account details to cybercriminals means that they have unauthorised access to your sensitive data, such as contact information, calendars, email communications, and more, which could lead to criminal activity such as BEC, identity theft , and other fraudulent activity,” MailGuard says. “Customers of trusted brand names such as Microsoft are targeted by cybercriminals due to the company’s expansive user base, so customers must remain vigilant and check twice before clicking on any potentially harmful links.”

MailGuard urges users to be wary of emails that:

  • Are not addressed to you by name.
  • Appear to be from a legitimate company but use poor English or omits personal details that a legitimate sender would include.
  • Are from businesses that you were not expecting to hear from, and/or
  • Take you to a landing page or website that is not the legitimate URL of the company the email is purporting to be sent from.

New-school security awareness training can enable your employees to recognize social engineering tactics so they can thwart phishing attacks.