A new phishing campaign has been detected that uses Google Cloud Services to fool victims into giving up their Office 365 credentials. The new campaign is part of a growing trend of disguising phishing attacks using legitimate cloud services.

The phishing attack starts like any other with an email containing a hyperlink that the recipient is requested to click. If the user clicks the link in the email, they are directed to Google Drive where a PDF file has been uploaded. When the file is opened, users are asked to click a hyperlink in the document, which appears to be an invitation to access a file hosted on SharePoint Online.

The PDF file asks the victim to click the link to sign in with their Office 365 ID. Clicking the link will direct the user to a landing page hosted using Google’s storage.googleapis.com. When the user arrives on the landing page, they are presented with an Office 365 login prompt that looks exactly like the real thing. After entering their credentials, they will be directed to a legitimate PDF whitepaper that has been obtained from a well-respected global consulting firm.

The campaign has been designed to make it appear that the victim is simply being directed to a PDF file that has been shared via Sharepoint, and the actual PDF file is displayed after the victim has divulged their credentials. It is therefore likely that the victim will not realize that their Office 365 credentials have been phished. The only sign that this is a scam is the source code on the phishing page, which even tech-savvy individuals would be unlikely to check.

This campaign was identified by researchers at Check Point, but it is just one of many similar campaigns to have been identified over the past few months. Since these domains are legitimate and have valid SSL certificates, they are difficult to detect as malicious. This campaign abused Google Cloud Services, but several other campaigns have been detected using the likes of IBM Cloud, Microsoft Azure and others to add legitimacy to the campaigns.

This campaign highlights the importance of providing security awareness training to the workforce and warning employees about the risks of clicking links in unsolicited emails, even those that link to genuine domains. An advanced email security solution should also be implemented to block malicious emails and ensure the majority of malicious messages are not delivered to inboxes. That is an area where TitanHQ can help.