The web browser is one of the most frequently used applications in any organization, and it is also one of the most common attack vectors. From drive-by downloads to malicious advertisements, the threats users encounter during routine browsing are diverse and constantly evolving. Implementing safe browsing practices is essential for protecting your organization from web-based attacks.
Understanding Web-Based Threats
Drive-by downloads occur when visiting a compromised or malicious website triggers an automatic download of malware without the user's knowledge or consent. These attacks exploit vulnerabilities in the browser itself, browser plugins, or the underlying operating system. A user does not need to click anything for the attack to succeed, simply loading the page is enough if the browser or its components have unpatched vulnerabilities.
Malvertising embeds malicious code within online advertisements displayed on otherwise legitimate websites. Because ad networks serve content dynamically, even well-known and trusted websites can inadvertently deliver malicious ads. Users see a legitimate page and have no reason to suspect danger, making malvertising particularly insidious.
Watering hole attacks target specific organizations by compromising websites that their employees frequently visit. Attackers identify industry forums, professional associations, or vendor portals frequented by the target organization, then inject malicious code into those sites. Because the compromised site is familiar and trusted, employees are unlikely to exercise the caution they might apply to an unknown website.
Browser Security Configuration
Keeping browsers updated is the single most important browser security measure. Modern browsers release security patches frequently, and enabling automatic updates ensures that known vulnerabilities are closed promptly. Configure browsers to check for updates daily and apply them without requiring user action.
Disable or remove unnecessary browser plugins and extensions. Each plugin expands the browser's attack surface. Flash, Java applets, and other legacy plugins should be completely removed from all organizational systems. For necessary extensions, maintain an approved list and block the installation of unauthorized extensions through group policy or mobile device management.
Enable built-in browser security features such as safe browsing warnings, phishing protection, and download scanning. Configure the browser to block pop-ups and prevent automatic file downloads. Set the default behavior for downloaded files to require explicit user confirmation before execution.
Recognizing Malicious Websites
Train users to verify website authenticity before entering any information. Check that the URL matches the expected domain exactly, watching for typosquatting attempts that use visually similar characters. Verify that HTTPS is active for any site handling sensitive data, though be aware that attackers also use HTTPS on phishing sites.
Be cautious with shortened URLs that obscure the true destination. Use URL preview tools or expansion services to reveal the actual destination before clicking. Avoid clicking links in emails or messages when you can navigate directly to the website by typing the known URL into the browser address bar.
Safe Download Practices
Download software only from official vendor websites or approved internal repositories. Avoid third-party download sites that bundle legitimate software with potentially unwanted programs or malware. Verify downloaded files using checksums or digital signatures when available.
Configure endpoint protection to scan all downloaded files automatically before they can be opened or executed. Implement application whitelisting on workstations to prevent unauthorized executables from running, even if a malicious file is successfully downloaded.
Sandboxing and Isolation
Browser isolation technology executes web content in a sandboxed environment separate from the local operating system. Even if a website successfully exploits a browser vulnerability, the attack is contained within the sandbox and cannot reach the user's system or the corporate network. Cloud-based browser isolation services render web content on remote servers and stream only a safe visual representation to the user's browser.
For organizations that cannot deploy full browser isolation, consider using virtual machines or containers for high-risk browsing activities such as research on unfamiliar websites. This approach limits the blast radius of any successful attack to the disposable virtual environment.
Browser Extensions for Security
Select a small number of vetted security extensions to enhance protection. Ad blockers reduce exposure to malvertising. Script blockers give advanced users control over which domains can execute JavaScript. URL reputation extensions provide real-time warnings about known malicious websites.
However, exercise caution when selecting extensions. Each extension has broad access to browsing data and can introduce its own vulnerabilities. Limit extensions to those from trusted publishers with established track records, and review permissions carefully before installation.
Safe browsing is a combination of technical controls and user awareness. By configuring browsers securely, keeping software current, and training users to recognize web-based threats, organizations can significantly reduce the risk posed by everyday internet use.
