6 Browser Threats Your Security Team Must Prepare for in 2025
▼ Summary
– Browser-based attacks are the leading cause of breaches in 2025, focusing on compromising business apps and data through employee web browsers.
– Attackers primarily use phishing with reverse-proxy AitM kits to intercept sessions and bypass most MFA, except passkeys in some cases.
– Malicious code delivery techniques like ClickFix trick users into running harmful commands, often distributing infostealer malware via various channels.
– Other key attack methods include malicious OAuth integrations, browser extensions, and file downloads, all exploiting browser access to apps.
– Effective detection requires browser-level visibility, as traditional email or network security tools struggle against these evolving, multi-channel attacks.
The browser has become the central hub for modern business operations, and with that shift comes a new frontier for cyber threats. Security teams must now focus their efforts on the browser as the primary attack surface, where adversaries are increasingly launching sophisticated campaigns aimed at compromising cloud applications and corporate data. Understanding these evolving tactics is no longer optional, it’s essential for building a resilient defense.
Attackers aren’t necessarily trying to break the browser itself. Their real objective is to infiltrate the third-party applications and services that power today’s enterprises. By targeting users who access these apps through browsers, threat actors can bypass traditional network perimeters and strike directly at the heart of business operations. Recent high-profile incidents, like the Snowflake and Salesforce breaches, illustrate just how devastating these attacks can be.
Let’s examine the six most critical browser-based threats that security professionals need to anticipate and counter.
Phishing for credentials and sessions remains one of the most direct and damaging attack methods. Modern phishing is no longer confined to email; it now spans instant messaging, social platforms, SMS, and even malicious ads. Attackers use advanced Attacker-in-the-Middle (AitM) kits that intercept live sessions, allowing them to bypass multi-factor authentication in real time. These toolkits are highly evasive, using dynamic code obfuscation and legitimate cloud services to avoid detection. Relying solely on email filters or blocklists is no longer sufficient, real-time browser monitoring is critical.
Another rising threat is malicious code delivery, often referred to as ClickFix or FileFix. These attacks deceive users into executing harmful commands by disguising them as routine actions, like solving a CAPTCHA or pasting text into a terminal. The result is often the delivery of information-stealing malware, which harvests credentials and session cookies. Because these lures are visually diverse and technically sophisticated, traditional security tools struggle to identify them. Detecting malicious clipboard activity directly in the browser offers a promising way to stop these attacks early.
Malicious OAuth integrations represent a stealthy and effective attack vector. By tricking users into granting excessive permissions to a rogue application, attackers gain direct access to business data without needing to steal credentials. This method bypasses even the strongest login protections, including phishing-resistant MFA. The recent Salesforce breaches highlight how dangerous this technique can be. Gaining visibility into OAuth grants across all browser-accessed applications, even unmanaged ones, is crucial for defense.
Dangerous browser extensions pose another serious risk. Malicious add-ons can capture login details, modify web content, and exfiltrate sensitive information. Attackers often compromise existing extensions or publish fake ones mimicking trusted brands. With limited visibility into which extensions employees install, organizations are vulnerable to large-scale data theft. Browser-level security tools can monitor extension behavior, flag risky permissions, and identify known-malicious code.
The distribution of malicious files through non-email channels is also on the rise. Attackers use malvertising, drive-by downloads, and weaponized file types like HTAs or SVGs to deliver malware or redirect users to phishing sites. While endpoint protection plays a role, observing file downloads within the browser provides an additional layer of defense, especially against client-side attacks that evade traditional sandboxing.
Finally, stolen credentials and MFA gaps often result from successful phishing or infostealer attacks. When multi-factor authentication isn’t enforced across all applications, stolen passwords can lead to full account takeovers. Many organizations struggle with inconsistent MFA deployment, legacy local logins, and shadow IT. Browser-level login monitoring offers a clear view of authentication practices, helping teams identify and remediate vulnerabilities before they’re exploited.
In today’s threat landscape, the browser is where attacks begin and often where they can be stopped. Organizations that gain visibility into browser activity will be far better equipped to defend against these evolving techniques.
(Source: Bleeping Computer)
