Personalized URL Phishing: Understanding the Threat of Email-Based Content Modification


In the ever-evolving landscape of cybersecurity threats, phishing remains one of the most pervasive and insidious forms of attack. From generic mass email campaigns, to highly sophisticated spear-phishing tactics, attackers continuously innovate to deceive unsuspecting victims. However, a new dimension to phishing has recently emerged, posing an even greater threat to individuals and organizations: personalized URL phishing.

Imagine receiving an email seemingly from a trusted source – a colleague, a friend, or a reputable company – containing a link that appears harmless at first glance. But what if that link is tailored specifically to you, incorporating information gleaned from the email?

Welcome to the world of personalized URL phishing, where attackers leverage email content to modify URLs and manipulate website content accordingly.


The Multi-Company Targeting Mechanism of Personalized URL Phishing

In the landscape of personalized URL phishing, attackers are leveraging sophisticated techniques to target multiple companies simultaneously, exploiting the unique attributes of each targeted organization to enhance the credibility of their attacks. A prime example is the dynamic modification of URLs to tailor the phishing content based on the recipient’s email domain.

Case Study

Dynamic URL Modification

Consider the following base URL used in a phishing attack:


When accessed directly, this URL presents a generic phishing page requesting email and password information. However, the true sophistication of the attack is revealed when the URL is concatenated with a fragment identifier that includes the recipient’s email address:


Here, the fragment identifier #[email protected] triggers a script that customizes the page based on the email address domain ( in this example).

Dynamic URL Modification

Mechanism of Content Modification

Upon receiving the URL with the email identifier, the phishing page dynamically alters its content to mimic the branding of the targeted organization. The process involves:

Extracting the Email Domain: The script parses the fragment identifier to isolate the domain portion of the email address.

Fetching the Favicon: Using the extracted domain, the script performs a lookup to retrieve the favicon from the company’s legitimate website (e.g.,

Image demonstrating content modification based on email address.
Image demonstrating content modification based on email address.

Altering the Page Appearance

The phishing page incorporates the favicon and possibly other branding elements (such as logos or color schemes) to create a convincing imitation of the company’s login page.

This technique significantly enhances the credibility of the phishing attempt, as users are more likely to trust a page that visually aligns with their organization’s branding.

Broader Implications and Impact

The ability to dynamically customize phishing pages based on email domains allows attackers to target multiple companies with a single URL template efficiently. This method reduces the effort required to create separate phishing pages for each organization while simultaneously increasing the effectiveness of the attack due to the personalized appearance.

Scalability: Attackers can scale their operations, targeting numerous companies without manually configuring each phishing page.

Increased Success Rates: Using company-specific branding elements increases the likelihood that recipients will be deceived, leading to higher rates of credential compromise.

Brand Damage and Trust Erosion: Successful phishing attacks not only jeopardize individual accounts but also damage the reputation of the targeted companies, eroding trust among their clients and employees.

Mitigation Strategies

To combat this sophisticated phishing technique, organizations can implement several defensive measures:

Advanced Email Filtering: Deploy email security solutions that detect and block emails containing suspicious URLs, particularly those using fragment identifiers in unconventional ways.

URL Scanning and Analysis: Use tools that scan and analyze URL behavior, including their ability to change content dynamically based on fragments or parameters.

User Education and Awareness: Train employees to recognize phishing attempts, emphasizing the importance of scrutinizing URLs and being cautious with emails requesting sensitive information.

Favicon and Branding Monitoring: Regularly monitor the use of your company’s branding elements online to detect and take down phishing pages that misuse them.

Zero-Trust Security Model: Implement a zero-trust approach where all internal and external requests are authenticated and authorized rigorously.

Real-Time Threat Intelligence: Leverage threat intelligence services that provide real-time updates on emerging phishing threats and tactics.

Future Trends and Predictions

AI and Machine Learning: Both attackers and defenders will increasingly use AI. Attackers may use AI to automate and refine phishing techniques, while defenders will use it to detect anomalies and improve filtering.

Enhanced Personalization: As data breaches continue to provide attackers with more personal information, phishing attacks will become even more customized and harder to detect.

Integration with Other Threat Vectors: Personalized phishing could be combined with other attack vectors, such as social media impersonation or voice phishing (vishing), to create multi-faceted attacks.

Regulatory Developments: Laws and regulations will continue to evolve, requiring organizations to adopt stricter cybersecurity measures and reporting protocols.

Organizations can better protect themselves and their users from these increasingly sophisticated cyber threats by understanding and addressing the mechanisms of personalized URL phishing. Combining technical references, user education, and continuous monitoring will be crucial in staying ahead of attackers.


Personalized URL phishing is a sophisticated tactic where cybercriminals customize phishing pages using extracted personal information and mimic multiple companies’ branding. This evolution in phishing poses severe risks, demanding comprehensive mitigation strategies like advanced email filtering, URL scanning, user education, and AI integration in defense.

Staying vigilant and proactive while fostering a culture of cybersecurity awareness is crucial to defending against these evolving threats and safeguarding our digital lives.

Bolster can help identify new and evolving phishing techniques targeting your business. Request a demo with us today to learn more.