Adversaries may gain access to a system through a user visiting a website over the normal course of browsing. Multiple ways of delivering exploit code to a browser exist (i.e., Drive-by Target), including: * A legitimate website is compromised, allowing adversaries to inject malicious code * Script files served to a legitimate website from a publicly writeable cloud storage bucket are modified by an adversary * Malicious ads are paid for and served through legitimate ad providers (i.e., Malvertising) * Built-in web application interfaces that allow user-controllable content are leveraged for the insertion of malicious scripts or iFrames (e.g., cross-site scripting) Browser push notifications may also be abused by adversaries and leveraged for malicious code injection via User Execution. By clicking "allow" on browser push notifications, users may be granting a website permission to run JavaScript code on their browser.(Citation: Push notifications - viruspositive)(Citation: push notification -mcafee)(Citation: push notifications - malwarebytes) Often the website used by an adversary is one visited by a specific community, such as government, a particular industry, or a particular region, where the goal is to compromise a specific user or set of users based on a shared interest. This kind of targeted campaign is often referred to a strategic web compromise or watering hole attack. There are several known examples of this occurring.(Citation: Shadowserver Strategic Web Compromise) Typical drive-by compromise process: 1. A user visits a website that is used to host the adversary controlled content. 2. Scripts automatically execute, typically searching versions of the browser and plugins for a potentially vulnerable version. The user may be required to assist in this process by enabling scripting, notifications, or active website components and ignoring warning dialog boxes. 3. Upon finding a vulnerable version, exploit code is delivered to the browser. 4. If exploitation is successful, the adversary will gain code execution on the user's system unless other protections are in place. In some cases, a second visit to the website after the initial scan is required before exploit code is delivered. Unlike Exploit Public-Facing Application, the focus of this technique is to exploit software on a client endpoint upon visiting a website. This will commonly give an adversary access to systems on the internal network instead of external systems that may be in a DMZ.
Correlated evidence where Safari/Chrome/WebKit-based processes issue network requests for uncommon or obfuscated JS resources followed by spawning of script interpreters, launchd or ad-hoc binaries, unusual child processes, or dynamic library loads into browser processes. Defender sees: proxy/HTTP logs with suspicious resource content + unifiedlogs/ASL showing browser/plugin crashes or extension loads + process events indicating child process creation and file writes to /var/folders or /tmp shortly after the fetch.
Post-compromise identity & session anomalies that follow a drive-by compromise: token reuse from new/unfamiliar IPs, anomalous sign-in patterns for previously inactive users, unexpected consent/grant events, or provisioning changes. Defender sees an endpoint/browser compromise (network + endpoint signals) followed by unusual IdP events: new refresh token issuance, consent/consent-grant events, odd MFA bypass patterns, or unusual OAuth client registrations.
Correlated evidence of browser or webview fetches to uncommon domains or mutated JS resources (proxy/NGFW logs + Zeek/HTTP logs) followed by unexpected interpreters or script engines executing (python, ruby, sh) spawned from browser processes or user sessions, rapid on-disk staging in /tmp, and outbound connections that deviate from baseline. Defender sees: uncommon resource fetch → short-lived child process executions from user browser context → file writes in temp directories → anomalous outbound C2-like connections.
User Training
User Training involves educating employees and contractors on recognizing, reporting, and preventing cyber threats that rely on human interaction, such as phishing, social engineering, and other manipulative techniques. Comprehensive training programs create a human firewall by empowering users to be an active component of the organization's cybersecurity defenses. This mitigation can be implemented through the following measures: Create Comprehensive Training Programs: - Design training modules tailored to the organization's risk profile, covering topics such as phishing, password management, and incident reporting. - Provide role-specific training for high-risk employees, such as helpdesk staff or executives. Use Simulated Exercises: - Conduct phishing simulations to measure user susceptibility and provide targeted follow-up training. - Run social engineering drills to evaluate employee responses and reinforce protocols. Leverage Gamification and Engagement: - Introduce interactive learning methods such as quizzes, gamified challenges, and rewards for successful detection and reporting of threats. Incorporate Security Policies into Onboarding: - Include cybersecurity training as part of the onboarding process for new employees. - Provide easy-to-understand materials outlining acceptable use policies and reporting procedures. Regular Refresher Courses: - Update training materials to include emerging threats and techniques used by adversaries. - Ensure all employees complete periodic refresher courses to stay informed. Emphasize Real-World Scenarios: - Use case studies of recent attacks to demonstrate the consequences of successful phishing or social engineering. - Discuss how specific employee actions can prevent or mitigate such attacks.
Restrict Web-Based Content
Restricting web-based content involves enforcing policies and technologies that limit access to potentially malicious websites, unsafe downloads, and unauthorized browser behaviors. This can include URL filtering, download restrictions, script blocking, and extension control to protect against exploitation, phishing, and malware delivery. This mitigation can be implemented through the following measures: Deploy Web Proxy Filtering: - Use solutions to filter web traffic based on categories, reputation, and content types. - Enforce policies that block unsafe websites or file types at the gateway level. Enable DNS-Based Filtering: - Implement tools to restrict access to domains associated with malware or phishing campaigns. - Use public DNS filtering services to enhance protection. Enforce Content Security Policies (CSP): - Configure CSP headers on internal and external web applications to restrict script execution, iframe embedding, and cross-origin requests. Control Browser Features: - Disable unapproved browser features like automatic downloads, developer tools, or unsafe scripting. - Enforce policies through tools like Group Policy Management to control browser settings. Monitor and Alert on Web-Based Threats: - Use SIEM tools to collect and analyze web proxy logs for signs of anomalous or malicious activity. - Configure alerts for access attempts to blocked domains or repeated file download failures.
Application Isolation and Sandboxing
Application Isolation and Sandboxing refers to the technique of restricting the execution of code to a controlled and isolated environment (e.g., a virtual environment, container, or sandbox). This method prevents potentially malicious code from affecting the rest of the system or network by limiting access to sensitive resources and critical operations. The goal is to contain threats and minimize their impact. This mitigation can be implemented through the following measures: Browser Sandboxing: - Use Case: Implement browser sandboxing to isolate untrusted web content and prevent malicious web pages or scripts from accessing sensitive system resources or initiating unauthorized downloads. - Implementation: Use browsers with built-in sandboxing features (e.g., Google Chrome, Microsoft Edge) or deploy enhanced browser security frameworks that limit the execution scope of active content. Consider controls that monitor or restrict script-based file generation and downloads commonly abused in evasion techniques like HTML smuggling. Application Virtualization: - Use Case: Deploy critical or high-risk applications in a virtualized environment to ensure any compromise does not affect the host system. - Implementation: Use application virtualization platforms to run applications in isolated environments. Email Attachment Sandboxing: - Use Case: Route email attachments to a sandbox environment to detect and block malware before delivering emails to end-users. - Implementation: Integrate security solutions with sandbox capabilities to analyze email attachments. Endpoint Sandboxing: - Use Case: Run all downloaded files and applications in a restricted environment to monitor their behavior for malicious activity. - Implementation: Use endpoint protection tools for sandboxing at the endpoint level.
Exploit Protection
Deploy capabilities that detect, block, and mitigate conditions indicative of software exploits. These capabilities aim to prevent exploitation by addressing vulnerabilities, monitoring anomalous behaviors, and applying exploit-mitigation techniques to harden systems and software. Operating System Exploit Protections: - Use Case: Enable built-in exploit protection features provided by modern operating systems, such as Microsoft's Exploit Protection, which includes techniques like Data Execution Prevention (DEP), Address Space Layout Randomization (ASLR), and Control Flow Guard (CFG). - Implementation: Enforce DEP for all programs and enable ASLR to randomize memory addresses used by system and application processes. Windows: Configure Exploit Protection through the Windows Security app or deploy settings via Group Policy. `ExploitProtectionExportSettings.exe -path "exploit_settings.xml"` Linux: Use Kernel-level hardening features like SELinux, AppArmor, or GRSEC to enforce memory protections and prevent exploits. Third-Party Endpoint Security: - Use Case: Use endpoint protection tools with built-in exploit protection, such as enhanced memory protection, behavior monitoring, and real-time exploit detection. - Implementation: Deploy tools to detect and block exploitation attempts targeting unpatched software. Virtual Patching: - Use Case: Use tools to implement virtual patches that mitigate vulnerabilities in applications or operating systems until official patches are applied. - Implementation: Use Intrusion Prevention System (IPS) to block exploitation attempts on known vulnerabilities in outdated applications. Hardening Application Configurations: - Use Case: Disable risky application features that can be exploited, such as macros in Microsoft Office or JScript in Internet Explorer. - Implementation: Configure Microsoft Office Group Policies to disable execution of macros in downloaded files.
Update Software
Software updates ensure systems are protected against known vulnerabilities by applying patches and upgrades provided by vendors. Regular updates reduce the attack surface and prevent adversaries from exploiting known security gaps. This includes patching operating systems, applications, drivers, and firmware. This mitigation can be implemented through the following measures: Regular Operating System Updates - Implementation: Apply the latest Windows security updates monthly using WSUS (Windows Server Update Services) or a similar patch management solution. Configure systems to check for updates automatically and schedule reboots during maintenance windows. - Use Case: Prevents exploitation of OS vulnerabilities such as privilege escalation or remote code execution. Application Patching - Implementation: Monitor Apache's update release notes for security patches addressing vulnerabilities. Schedule updates for off-peak hours to avoid downtime while maintaining security compliance. - Use Case: Prevents exploitation of web application vulnerabilities, such as those leading to unauthorized access or data breaches. Firmware Updates - Implementation: Regularly check the vendor’s website for firmware updates addressing vulnerabilities. Plan for update deployment during scheduled maintenance to minimize business disruption. - Use Case: Protects against vulnerabilities that adversaries could exploit to gain access to network devices or inject malicious traffic. Emergency Patch Deployment - Implementation: Use the emergency patch deployment feature of the organization's patch management tool to apply updates to all affected Exchange servers within 24 hours. - Use Case: Reduces the risk of exploitation by rapidly addressing critical vulnerabilities. Centralized Patch Management - Implementation: Implement a centralized patch management system, such as SCCM or ManageEngine, to automate and track patch deployment across all environments. Generate regular compliance reports to ensure all systems are updated. - Use Case: Streamlines patching processes and ensures no critical systems are missed. *Tools for Implementation* Patch Management Tools: - WSUS: Manage and deploy Microsoft updates across the organization. - ManageEngine Patch Manager Plus: Automate patch deployment for OS and third-party apps. - Ansible: Automate updates across multiple platforms, including Linux and Windows. Vulnerability Scanning Tools: - OpenVAS: Open-source vulnerability scanning to identify missing patches.