Cybercriminals Get Creative With Google Services

Security researchers have reported an uptick in cyberattackers weaponizing Google services to sneak past defensive tools and steal credentials, credit card details, and other personal information.

The Armorblox threat research team today published their analysis of five targeted phishing campaigns they call "the tip of a deep iceberg." These attacks take advantage of several Google services, including Google Forms, Google Docs, Google Site, and Firebase, Google's mobile platform for app development.

"Google is offering all these services that make building applications a lot easier," says Arjun Sambamoorthy, co-founder and head of engineering at Armorblox, of the recent increase in these attacks. "This actually encourages attackers to move toward Google instead of hosting a site themselves … this also adds credibility, in some sense, to phishing sites hosted on Google." 

Most employees, and the security tools they depend on, regularly use and trust Google services – a trust that attackers are well aware of and aim to exploit in these campaigns, he notes.

"There's a whole spectrum of attacks," Sambamoorthy says. While some of the scams appear sophisticated, researchers believe the accessibility of Google could mean an individual or smaller-scale group could be responsible for this activity. The goal appears to be data theft.

One credential phishing email, for example, spoofs American Express and informs recipients they neglected to provide information while validating their card. A link is placed to redirect the reader to a page where they can enter their data. This page, hosted on Google Forms, contains American Express branding and prompts the victim for login credentials, credit card details, and even their mother's maiden name – a common security question, the researchers point out.

In another attack, criminals impersonate an enterprise security team with an email informing a victim they haven't received a "vital" message due to a storage quota issue. The email contains a link for them to verify their data and restart email delivery. The URL redirects to a fake login page hosted on Firebase, where they see their email address prefilled above a password request.

"Imitating 'quick fill' techniques used by forms on legitimate websites is commonly used by cybercriminals to lull victims into a false sense of security," Sambamoorthy wrote in a blog post on the findings, noting the URL goes through one redirect before landing on the Firebase page, concealing the attack flow for any security technology that may attempt to follow it.

Most people use Google Docs in their day-to-day work and may not notice the payslip scam that weaponizes the popular service. Researchers noticed attackers impersonating a business' payroll team with an email containing payslip details. The email, which had the recipient's name in the subject and body to convey urgency, contained a link for readers to check whether their personal data is accurate.

"This is a variant of the more classic payroll diversion fraud, where cybercriminals impersonate employees and try to divert payroll funds to their own accounts," Sambamoorthy wrote.

In another brand impersonation attack, cybercriminals use Google Sites to create a credential phishing page resembling Microsoft Teams. To trick victims into visiting the site, they create an email pretending to come from the company's IT team, asking readers to view a secure Teams message.

Training Employees to Spot Cybercrime
None of the aforementioned brands will request credentials using a Google site, Sambamoorthy emphasized, which is "a fundamental thing to keep in mind" for all employees. If someone is the victim of a social engineering attack, they should be instructed to check in with colleagues to see whether others received the same message before sharing credentials.

"Most of these attackers try to insert themselves into a digital workflow that already exists in the organization," says Abhishek Iyer, director of product marketing at Armorblox, noting this is another factor employees should be aware of.

Both Sambamoorthy and Iyer encourage businesses to adopt multifactor authentication (MFA) wherever possible. This way, even if the attackers steal credentials, it will be increasingly difficult for them to break into other accounts with the same username and password. Iyer also notes that large enterprises that implement MFA may work with vendors that don't, which could prove a risk to the organization. His advice: Educate vendors and ensure they're also using MFA.