Fortinet’s FortiGuard Labs recently uncovered a new and sophisticated PayPal phishing scam that exploits a loophole in Microsoft365 tools. This attack uses legitimate-looking emails and genuine PayPal login pages to deceive users into linking their PayPal accounts to unauthorized addresses. The scammers bypass traditional phishing detection mechanisms by leveraging Microsoft365’s Sender Rewriting Scheme (SRS), which rewrites sender addresses to pass SPF, DKIM, and DMARC checks, making the emails appear legitimate. As a result, users may unknowingly provide their login details, granting attackers access to their accounts and posing significant financial risks.
The phishing attack begins with an email that appears to come from a valid PayPal address, containing a legitimate-looking request for payment. Victims are instructed to log into their PayPal accounts through a link in the email to review the request. Once the victim enters their credentials, their account is linked to the scammer’s unauthorized address, allowing the attacker to take control of the victim’s PayPal account without raising immediate suspicion. This method bypasses PayPal’s built-in phishing detection protocols and exploits the platform’s legitimate functionality to trick users.
Fortinet’s Chief Information Security Officer, Carl Windsor, emphasized the unique nature of this scam, noting that it doesn’t rely on traditional phishing tactics. Unlike other scams that use deceptive links or attachment downloads, this one relies on using valid-looking emails, URLs, and PayPal pages. This makes it particularly dangerous, as users may believe they are interacting with the actual PayPal platform and are less likely to recognize the scam. Windsor advised that awareness and caution are crucial in avoiding such scams, as users are often the first line of defense against these kinds of attacks.
To mitigate the risk of falling victim to this scam, Fortinet recommends that PayPal users follow best practices in cybersecurity, such as enabling two-factor authentication (2FA), avoiding unsolicited emails, and verifying URLs before clicking on any links. It’s also critical for users to avoid entering login credentials on websites unless they are certain of the site’s authenticity. Educating individuals to become a “Human Firewall” can significantly reduce the likelihood of falling prey to these sophisticated phishing tactics.
