Believe it or not: attackers have been known to send seemingly legitimate emails from trusted brand names to harvest user data…

Believe it…attackers use “trusted” brand names to launch their attacks

Real world example: The Case of the “Google Docs” Phishing Scam

One of the most intriguing and widespread phishing scams occurred in May 2017, when attackers launched a sophisticated attack disguised as a Google Docs invitation. This attack not only fooled thousands of users but also exploited trust in Google’s ecosystem.

What Happened?

The attack started with victims receiving an email that appeared to come from someone they knew. The email contained an invitation to open a Google Docs file. It looked legitimate because the attackers used Google’s own infrastructure, making it harder to detect.

The Deception

  • When users clicked on the link, they were redirected to a fake OAuth permissions page.
  • The page asked for access to the user’s Gmail account, contacts, and Google Drive.
  • Many users, seeing the familiar Google interface and a request that seemed reasonable, approved the permissions.

The Impact

  • Once the attackers gained access, they:

    1. Harvested user data: They collected contact lists, emails, and other sensitive information.
    2. Spread further: They sent the same phishing email to everyone in the victim’s contact list, rapidly expanding the attack.
    3. Accessed private files: If users had sensitive data in their Google Drive or email accounts, the attackers could exploit it.

The Scale

In just a few hours, the phishing campaign affected millions of users worldwide. It was so convincing that even security experts and journalists fell for it.

Why it was so effective

  1. Legitimacy: The attack used Google’s real OAuth system to request permissions, making it look genuine.
  2. Trust in Google: Many users didn’t suspect foul play because the emails came from trusted contacts and appeared to involve Google Docs.
  3. Rapid propagation: By accessing contact lists, the scam spread exponentially, leveraging social trust.

Google’s Response

Google acted quickly to mitigate the attack by:

  • Disabling the malicious app within an hour of discovering it.
  • Revoking permissions for all affected accounts.
  • Enhancing OAuth protection and introducing warnings for unfamiliar apps requesting permissions.

Lessons Learned

  1. Always verify links: Even if an email seems to come from a trusted source, double-check links and sender details.
  2. Be wary of permission requests: Only grant permissions to apps you trust and understand.
  3. Enable two-factor authentication: This provides an extra layer of security, even if attackers gain access to your credentials.
  4. Educate users: Phishing attacks rely on human error, so awareness is critical.

 

This phishing campaign stands out because it highlights how attackers can exploit trusted platforms and services. It also led to significant improvements in phishing detection and OAuth security across the tech industry.