Deploys remote browser isolation (RBI) as a core component of a Zero Trust architecture. Implements isolation policies with URL categorization and risk-based routing, content disarming and reconstruction (CDR) for file sanitization, data loss prevention controls within isolated sessions, and integration with Secure Web Gateway and ZTNA platforms. Based on Cloudflare Browser Isolation, Menlo Security, and Zscaler RBI approaches. Use when hardening web access against zero-day exploits, phishing, credential theft, and browser-based data exfiltration.
Deploys remote browser isolation (RBI) as a core component of a Zero Trust architecture. Implements isolation policies with URL categorization and risk-based routing, content disarming and reconstruction (CDR) for file sanitization, data loss prevention controls within isolated sessions, and integration with Secure Web Gateway and ZTNA platforms. Based on Cloudflare Browser Isolation, Menlo Security, and Zscaler RBI approaches. Use when hardening web access against zero-day exploits, phishing, credential theft, and browser-based data exfiltration.
When deploying remote browser isolation as part of a Zero Trust security architecture
When protecting users from zero-day browser exploits and drive-by downloads
When implementing content disarming and reconstruction for file downloads
When enforcing data loss prevention policies for web browsing sessions
When securing access to untrusted or uncategorized websites
When integrating browser isolation with existing SWG and ZTNA infrastructure
When protecting against phishing and credential theft via isolated rendering
Prerequisites
Familiarity with Zero Trust architecture principles and network security
Understanding of Secure Web Gateway (SWG) and proxy deployment models
Access to a test or lab environment for policy validation
Python 3.8+ with required dependencies installed
DNS and proxy infrastructure for traffic routing
Instructions
Phase 1: URL Categorization and Risk Classification
Build a URL categorization engine that classifies websites by risk level to
determine isolation policy. URLs are scored based on threat intelligence feeds,
domain reputation, content category, and historical risk indicators.
from agent import BrowserIsolationPolicyEngine
engine = BrowserIsolationPolicyEngine(
organization="Acme Corp",
default_isolation_mode="isolate_risky",
)
# Classify a URL and determine isolation action
result = engine.classify_url("https://docs.google.com/spreadsheets/d/abc123")
print(f"Category: {result['category']}")
print(f"Risk Level: {result['risk_level']}")
print(f"Isolation Action: {result['action']}")
# Output: Category: cloud_productivity# Risk Level: low# Action: allow_direct
result = engine.classify_url("https://unknown-sketchy-domain.xyz/download.html")
()
()
()
print
f"Category: {result['category']}"
print
f"Risk Level: {result['risk_level']}"
print
f"Isolation Action: {result['action']}"
# Output: Category: uncategorized
# Risk Level: high
# Action: full_isolation
Phase 2: Isolation Policy Configuration
Define isolation policies that map URL categories and risk levels to specific
isolation modes and DLP restrictions. Policies support granular controls including
clipboard, file download, upload, and printing restrictions.
Phase 3: Content Disarming and Reconstruction (CDR)
Implement CDR processing to sanitize downloaded files by deconstructing them,
stripping potentially malicious elements (macros, embedded objects, scripts),
and reconstructing clean versions that preserve usability.
# Process a file through CDR
cdr_result = engine.process_file_cdr(
file_path="/tmp/downloads/quarterly_report.docx",
source_url="https://partner-portal.example.com/reports/q4.docx",
cdr_profile="strict",
)
print(f"Original file: {cdr_result['original']['filename']}")
print(f"Original size: {cdr_result['original']['size_bytes']} bytes")
print(f"Threats found: {cdr_result['threats_found']}")
for threat in cdr_result['threats_detail']:
print(f" - {threat['type']}: {threat['description']} [{threat['action']}]")
print(f"Clean file: {cdr_result['reconstructed']['filename']}")
print(f"Clean size: {cdr_result['reconstructed']['size_bytes']} bytes")
print(f"File integrity preserved: {cdr_result['reconstructed']['usable']}")
# Example output:# Original file: quarterly_report.docx# Original size: 245760 bytes# Threats found: 3# - macro: VBA macro with AutoOpen trigger [STRIPPED]# - embedded_ole: Embedded OLE object (executable) [STRIPPED]# - external_link: External template reference [STRIPPED]# Clean file: quarterly_report_clean.docx# Clean size: 198432 bytes# File integrity preserved: True
Phase 4: Session Control and Monitoring
Implement real-time session monitoring for isolated browsing sessions with
keystroke logging policy, clipboard interception, and download tracking.
Integrate with SIEM for security event correlation.
Integrate browser isolation with the broader Zero Trust architecture including
identity provider, device posture checks, and conditional access policies.
