Researchers at Check Point have observed a phishing campaign that, to avoid detection, abused servers belonging to Adobe, Samsung, and the University of Oxford. The attackers used several layers of deception to disguise their phishing emails as legitimate.
The phishing emails purported to come from Microsoft and informed recipients that they’d received a voicemail on their Office 365 account. If the user clicked the link in the email, they’d be redirected through a legitimate server before landing on a spoofed Office 365 login page designed to steal their credentials.
The redirection step was accomplished using an Adobe Campaign open redirect link belonging to Samsung Canada, meant for the company’s email campaigns. Open redirects enable anyone to craft a URL that will route a user through the server hosting the URL before sending them on to the specified website. In this case, the attackers used the open redirect link from Samsung’s email campaign for Cyber Monday in 2018 and modified it to point to their phishing page.
“The technique of using Adobe Campaign open redirect was initially discovered in September 2019 on the domain belonging to Adobe itself,” the researchers write. “In the last few months, it’s been widely abused for phishing purposes. To evade detection, attackers abuse open and reputable Adobe Campaign servers to redirect potential victims to their own phishing websites. This means that the link embedded in the phishing email is part of a trusted domain – one that unknowingly redirects victims to the phishing website.”
The attackers also managed to abuse the University of Oxford’s email servers to disguise the origin of the emails.
“Using legitimate Oxford SMTP servers allowed the attackers to pass the reputation check for the sender domain,” Check Point says. “In addition, there was no need to compromise actual email accounts to send phishing emails because they could generate as many email addresses as they wanted.”
Finally, the phishing kit itself was hosted on a compromised WordPress site. It would generate a new directory for each visitor, as well as unique, obfuscated source code to avoid detection by security tools.
“The second layer of redirection is used to distance the final phishing page from the original email,” the researchers explain. “In this case, the attackers used several compromised WordPress sites which contain malicious redirect code. Introducing another redirection layer enables the attackers to circumvent security solutions that investigate the links within the email. Thus the URL within the email points to a WordPress site instead of a suspicious-looking phishing page.”
Attackers will never stop finding new ways to defeat security technologies. New-school security awareness training can give your organization an essential layer of defense by enabling your employees to recognize phishing emails that slip through the cracks.
Check Point has the story: https://research.checkpoint.com/2020/phishing-campaign-exploits-samsung-adobe-and-oxford-servers/