The frequency and sophistication of attacks targeting web browsers have surged dramatically in recent years. These “browser-based attacks” exploit the fact that browsers serve as the primary gateway to business applications, data, and cloud services, making them a prime target for threat actors.

Understanding Browser-Based Attacks

At their core, browser-based attacks are not about compromising the browser itself—they aim to infiltrate the applications and services accessed through it. Modern attackers focus on third-party SaaS platforms, where sensitive business data resides, and leverage compromised credentials or session tokens to extract information or conduct ransomware attacks.

The shift to decentralized cloud applications and remote work has made users more exposed to malicious content across multiple channels, including email, messaging apps, social media, and in-app notifications. As a result, the browser has become a central attack surface that security teams cannot ignore.

Six Key Browser-Based Attack Types

1. Credential and Session Phishing
   Phishing remains a top attack vector, now operating across multiple channels. Modern phishing campaigns use sophisticated tools to bypass MFA, obfuscate pages, and leverage legitimate cloud services to host malicious links. Attackers aim to steal credentials or session cookies to compromise SaaS apps, often without triggering traditional security alerts.
2. Malicious Copy & Paste (ClickFix, FileFix, etc.)
   Techniques like ClickFix trick users into executing commands by copying malicious code from the browser clipboard. Variants such as FileFix leverage file explorer or terminal prompts to run commands, frequently delivering infostealer malware or harvesting session credentials.
3. Malicious OAuth Integrations (Consent Phishing)
   Attackers exploit OAuth permissions by tricking users into authorizing malicious apps. These attacks bypass traditional login and MFA protections, giving attackers direct access to SaaS accounts. Recent Salesforce breaches highlight the scale and effectiveness of these attacks.
4. Malicious Browser Extensions
   Extensions are another vector for compromise. Threat actors can create or hijack browser extensions to capture login credentials, session tokens, and other sensitive data. Many extensions bypass web store security checks, making it difficult for organizations to monitor employee-installed extensions.
5. Malicious File Delivery
   Attackers continue to distribute malicious files through non-email channels, including malvertising, drive-by downloads, and HTML Applications (HTAs). SVG files and client-side phishing pages are increasingly used to deliver malware or capture credentials stealthily, highlighting the need for endpoint and browser-level file monitoring.
6. Exploited Credentials and MFA Gaps
   Stolen credentials from phishing or infostealer malware remain highly effective, especially when accounts lack mandatory MFA. Modern enterprises with hundreds of applications often have unprotected accounts or legacy “ghost logins” that can be exploited at scale. Browser monitoring helps identify these vulnerabilities before attackers can abuse them.

Conclusion

As business workflows continue to move online, the browser has become both the primary point of access and the weakest link for many organizations. Detecting and mitigating browser-based attacks requires visibility into user behavior, app interactions, and authentication flows.

Security teams should prioritize implementing tools that offer browser-level detection and response capabilities, protect against credential theft, session hijacking, malicious OAuth authorizations, risky extensions, and unmonitored file downloads. By focusing on the browser, organizations can close critical gaps and reduce the attack surface for identity and data breaches.

Source: https://thehackernews.com/2025/09/6-browser-based-attacks-security-teams.html