Hackers Exploit Imageless QR Codes in Phishing Attacks via HTML Tables
In a recent development, cybercriminals have innovated their phishing tactics by creating QR codes without traditional images, instead constructing them using HTML tables. This method effectively bypasses many email security measures, posing a significant threat to users.
The Emergence of Imageless QR Codes
Between December 22 and December 26, 2025, security researchers observed phishing emails that featured QR codes composed entirely of HTML table elements. These emails contained minimal text alongside a QR code urging recipients to scan it. Upon scanning, users were redirected to malicious websites designed to steal sensitive information.
Technical Construction of HTML-Based QR Codes
Traditionally, QR codes are embedded as images within emails. However, in this campaign, attackers utilized HTML tables to create the QR code pattern. Each table cell was styled with specific background colors to form the black and white modules characteristic of QR codes. This approach allows the QR code to function normally when scanned but evades detection by email security systems that typically analyze image attachments.
An example of such an HTML-based QR code is as follows:
“`html
“`
This method exploits a blind spot in many secure email gateways, as these systems may not inspect HTML tables for potential graphical structures, allowing the malicious QR code to slip through undetected.
Implications for Email Security
The use of HTML-based QR codes in phishing attacks highlights the need for advanced detection mechanisms. Traditional email security tools may overlook such constructs, as they are designed to scan for malicious links in text or image attachments. This technique underscores the importance of comprehensive content analysis that includes the inspection of HTML elements for potential threats.
Recommendations for Users and Organizations
To mitigate the risks associated with this new phishing tactic, consider the following measures:
1. Exercise Caution with Unsolicited Emails: Be wary of emails from unknown senders, especially those prompting you to scan QR codes or click on links.
2. Verify QR Codes Before Scanning: If you receive a QR code via email, verify its authenticity through other means before scanning.
3. Enhance Email Security Protocols: Organizations should update their email security systems to detect and analyze complex HTML structures that may conceal malicious content.
4. Educate Employees: Regular training sessions can help employees recognize and avoid phishing attempts, including those involving QR codes.
By staying informed about evolving phishing techniques and implementing robust security measures, individuals and organizations can better protect themselves against such sophisticated attacks.
