Why Shortened URLs Pose a Security Risk

Patrick_Yu

Shortened URLs are widely used in the digital world. They are small, concise links that replace long web addresses, making them easier to share across social media, emails, and text messages. Popular services like Bitly and TinyURL have become household names for this reason. Despite their convenience, shortened URLs also carry significant risks. They obscure the actual destination of a link, creating opportunities for hackers, scammers, and other cybercriminals to exploit unsuspecting users. This article explores how shortened URLs work, their history, the security risks they pose, and actionable ways to protect yourself. 

What is a shortened URL? 

A shortened URL is a condensed version of a full web address. URL shortening services transform a long URL into a smaller, more manageable link. For instance, a URL like https://example.com/research-study-2024-long-title might be turned into https://bit.ly/abc123. 

These shortened links are beneficial in several ways: 

• Compactness: They reduce clutter and make links more visually appealing. 
• Ease of sharing: Shortened URLs fit better in platforms like Twitter, which impose character limits, or in SMS messages. 
• Tracking capabilities: Many services allow users to track how often a link is clicked and gather data about the users who interact with it. 

However, while they simplify sharing, they also hide the full destination, which can lead to misuse. 

A brief history of URL shorteners

The concept of shortening URLs began in 2002 with TinyURL, one of the first services to offer this functionality. It solved a specific problem: long web addresses that broke when pasted into emails or forums. TinyURL quickly gained popularity, and competitors like Bitly soon emerged. 

By 2009, URL shorteners became a necessity with the rise of X (Formerly Twitter), which limited tweets to 140 characters. Services like Bitly not only offered link shortening but also introduced advanced features such as analytics and branded URLs. Today, shortened URLs are used by businesses, marketers, and everyday internet users. Despite their utility, the ability to mask link destinations has also made them a tool for cybercriminals. 

How do URL shorteners work? 

The technology behind URL shorteners is straightforward. When you enter a long URL into a shortening service, the platform generates a new, unique short link. This link redirects users to the original destination. 

Here’s how the process works: 

1. Input: The user submits a long URL to the shortening service. 
2. Database storage: The service stores the full URL in its database and associates it with a unique identifier. 
3. Shortened URL creation: The unique identifier is appended to the service’s domain to create a new, shorter link. 
4. Redirection: When someone clicks the shortened link, the service retrieves the original URL from its database and redirects the user’s browser to the intended site. 

While efficient, this system creates a layer of abstraction, preventing users from knowing where the link will lead until they click it. 

Security risks of shortened URLs 

Shortened URLs may seem harmless, but their design creates multiple security vulnerabilities. These risks include: 

• Obscured destinations: A shortened URL does not reveal its target, making it easy for malicious actors to disguise harmful sites. For example, https://bit.ly/3xyzabc gives no indication whether the link leads to a trusted website, a phishing page, or a malware download. 
• Phishing attacks: Phishing involves tricking users into revealing sensitive information by pretending to be a legitimate entity. Shortened URLs are a perfect tool for this, as they allow attackers to hide fake login pages that steal credentials or financial details. 
• Malware distribution: Clicking a malicious shortened link can initiate the download of malware, ransomware, or spyware. These programs can damage your device, steal data, or monitor your activities. 
• Service vulnerabilities: URL shortener services themselves can be compromised. If hackers gain access to a service’s database, they can alter existing shortened URLs to redirect users to malicious sites. 
• Data harvesting: Shortened URLs often include tracking mechanisms. While useful for marketers, this can also be used by attackers to collect information such as your location, device type, and browsing behavior without your knowledge. 
• Link expiration and reuse: Some services recycle shortened URLs after they expire. This means a link you once trusted could later be reused to redirect to harmful content. 

Real-world examples of security risks 

Several incidents highlight the dangers associated with shortened URLs: 

1. New Phishing Scam with Google Drawings and WhatsApp Shortened Links: In August 2024, a phishing campaign exploited Google Drawings and WhatsApp’s URL shortener to target Amazon customers. The attackers used a phishing email linking to a graphic hosted on Google Drawings, embedding shortened URLs to a fake Amazon login page designed to steal credentials. The use of trusted platforms like Google and multiple layers of shortened URLs helped the attackers bypass security filters and trick users. After harvesting sensitive information, victims were redirected to the legitimate Amazon login page to avoid suspicion. 
2. Sketchy Link Shortening Service: Prolific Puma is a DNS-based threat actor operating a large underground link-shortening service used by cybercriminals for phishing, scams, and malware distribution. This service creates massive numbers of algorithmically generated domains, which are then used to obfuscate malicious activities by layering redirections. In one campaign, Prolific Puma’s shortened links redirected users to phishing pages and browser malware, demonstrating their role in enabling sophisticated cybercrime. Prolific Puma has registered tens of thousands of domains, consistently evading detection by using cheap registrars and leveraging DNS tactics. 

How to identify malicious shortened URLs 

Identifying whether a shortened URL is safe can be challenging, but you can reduce your risk with these tips: 

• Hover over links: On a desktop, hovering over a shortened URL reveals the full destination in your browser’s status bar. 
• Preview links: Many shortener services allow you to preview the destination before clicking. For example, adding a + at the end of a Bitly link (https://bit.ly/example+) will show its full URL. 
• Check for HTTPS: Ensure the destination URL uses HTTPS, which provides a layer of security by encrypting data between your browser and the site. 
• Use link-checking tools: Services like VirusTotal or Norton Safe Web can analyze links for potential threats. 

Alternatives to URL shorteners 

If the risks of shortened URLs concern you, consider these alternatives: 

1. Use full URLs: Whenever possible, share the original link. It may be longer, but it provides full transparency. 
2. Branded short links: Some services allow you to create custom short links with your domain name (e.g., https://brandname.co/promo), which enhances trust. 
3. QR codes: Converting links into QR codes offers an alternative for easy sharing, particularly in printed materials or presentations. 
4. Link descriptions: When sharing a link, provide context or a description so users know what to expect. 

Should you continue using shortened URLs? 

Shortened URLs are a useful tool for convenience and tracking, but they require caution. Whether you should continue using them depends on your specific needs and your ability to mitigate risks. 

Best practices 

If you decide to use or interact with shortened URLs, follow these best practices: 

• Stick to reputable services: Use trusted platforms like Bitly, TinyURL, or branded shorteners. 
• Verify sources: Only click on links from trusted individuals or organizations. 
• Preview first: Always preview the destination if the link seems suspicious. 
• Educate others: Share knowledge about the risks of shortened URLs with colleagues, friends, and family. 

Conclusion 

Shortened URLs are a double-edged sword. While they simplify link sharing and provide valuable analytics, their ability to obscure destinations makes them a tool for cybercriminals. By understanding how these links work and the risks they pose, you can navigate the digital world more safely. Take steps to verify links, use security tools, and educate yourself on best practices. With vigilance, you can enjoy the benefits of shortened URLs while avoiding their dangers. Always pause, preview, and think before you click.

Recommended Products

TravelMate P2 Buy Now	TravelMate P4 Buy Now