User-Agent (UA) switchers, software which allow users to change the user-agent string sent by their browser, may seem like a benign tool used for convenience or testing purposes. However, from the perspective of online businesses, UA switchers pose significant challenges, including security risks, reduced data accuracy, and the potential for fraud. While UA switchers do serve legitimate purposes for developers and privacy-conscious users, they can also undermine key business operations.
UA switchers are not some esoteric dark web group of applications, but are now viewed as mainstream and accessible to every individual as plugins or extensions to almost every browser out there e.g. User-Agent Switcher for Chrome/Firefox. At the same time there are established testing platforms like Playwrite (Microsoft) and Puppeteer (Google) that provide both legitimate software testers and cyber criminals the ability to automate large scale and complex browser spoofing/tampering.
Some of the main risks that UA switchers present to online businesses include:
1. Increased Risk of Fraud
Many online businesses rely on the user-agent string as part of their fraud detection and prevention systems. However, UA switchers make it easier for fraudsters to mimic legitimate users, evade security measures, and bypass identity verification processes. By disguising their true browser or device, bad actors can impersonate different users, making it more difficult for businesses to detect suspicious behavior.
A common tactic is using a UA switcher to impersonate different browsers and devices to bypass fraud detection systems. For instance, someone trying to buy multiple sets of concert tickets (maximum purchase number per customer is trying to be enforced) can change their profile so that they look like a completely different user on a different device and sometimes in a different location coupled with a VPN.
This weakens an online business’s ability to maintain fairness during limited releases (e.g., concert tickets), resulting in bad customer experiences as bots hoard items, while real customers are left empty-handed.
2. Bypassing Security Mechanisms
Many businesses also rely on the user-agent string to tailor content or security measures to specific devices or browsers. For example, a website might present a CAPTCHA or other challenges to certain user-agent strings that are commonly associated with bots or automated scripts. By changing the user-agent string to a common or trusted browser type (like Chrome or Firefox), attackers can bypass these defenses, gaining access to restricted areas or performing unauthorized actions.
Cyber criminals often use UA switchers to evade web application firewalls or bot detection mechanisms that rely on the user-agent to filter out harmful traffic. This makes it harder for businesses to protect themselves against automated attacks such as distributed denial-of-service (DDoS) or credential stuffing, which flood websites with login attempts using stolen data.
3. Skewed Analytics and Reporting
For many businesses, accurate data on user behavior is crucial for decision-making. Marketers rely on user-agent data to understand which devices and browsers are being used to access their websites. This data helps optimize the user experience and tailor content to specific audiences. However, when users employ UA switchers, this information is distorted, leading to inaccurate reports on device usage, browser market share, and traffic sources.
A UA switcher can manipulate desktop visits to appear as mobile traffic, or vice versa. This can skew web analytics insights and lead to businesses favoring optimizations of their website for the wrong device channel. If many users are masking their user agents, businesses may also misinterpret which platforms are popular, leading to misguided marketing and development strategies.
4. Enabling Automated Attacks
UA switchers can be used in combination with other tools to automate malicious activities on websites, such as content scraping, brute force attacks, or automating purchases in e-commerce environments. These automated attacks often go undetected by mimicking human browsing behavior, and UA switchers help attackers blend in with normal traffic.
In an e-commerce context, bots powered by UA switchers are commonly used to purchase limited-stock items, like concert tickets or sneakers, much faster than humans. This results in genuine customers being locked out of purchases while resellers use bots to snatch up products, contributing to a poor user experience and revenue loss for businesses.
5. Compromising Website Integrity and Security
Websites are often built to serve different content based on the type of browser or device being used. By switching the user-agent, users can access versions of the site not intended for their actual device. This can lead to vulnerabilities being exposed, as certain versions of websites (e.g., mobile versions) may not be as thoroughly tested for.
A cyber criminal using a UA switcher to impersonate a mobile user might exploit a mobile-specific vulnerability that would not be present in the desktop version of the site. These targeted attacks can result in data breaches, which harm a business’s reputation and could lead to regulatory fines under data protection laws like the GDPR.
6. Circumventing Geo-Restrictions
Some businesses enforce Geo-restrictions to comply with licensing agreements or regulations. For example, streaming services and content providers may limit access to certain regions. By using a UA switcher in combination with a VPN (a common pairing), users can disguise their location and access restricted content, violating the terms of service and potentially exposing businesses to legal risks.
A user in a region where certain streaming content is not licensed can use a VPN/UA switcher combination to appear as if they are accessing the service from an authorized location. This undermines the content provider’s business model and may breach licensing agreements, putting the business at legal risk.
Mitigating the Risks of UA Switchers with DeviceAssure by DeviceAtlas
To address the risks posed by UA switchers, businesses can implement several strategies:
- Device Verification: DeviceAssure’s patented algorithm, in conjunction with 20 years of device identification expertise, compares device and browser details against known good profiles. This expertise allows for the real-time identification of potentially malicious actors by being able to report when a device it not what it appears to be, even when the user-agent is saying it is something else.
- Device Tampering Detection: DeviceAssure gathers dozens of device and browser properties and can detect abnormal property patterns that help businesses identify and block malicious traffic, even if it comes from seemingly legitimate user agents.
