How to Fix Burp Suite Collaborator

In this tutorial, you'll learn about How to Fix Burp Suite Collaborator. We cover key concepts, practical examples, and best practices to help you understand and apply this topic effectively.

Burp Collaborator does not show any interactions, or the collaborator client reports "Failed to retrieve interactions." The Collaborator server is unreachable or the poll request fails.

The Wrong Way

# Using the default public Collaborator server without testing connectivity

Public Collaborator may be blocked by corporate firewalls or DNS filters.

The Right Way

Step 1: Test Collaborator connectivity

# Burp → Project Options → Collaborator → "Test connectivity"
# Expected: "Collaborator connectivity check: passed"
# If "failed", check:
# - Outbound HTTPS to *.burpcollaborator.net
# - DNS resolution for collaborator subdomains

Step 2: Use a custom Collaborator server

# For isolated networks, run a local Collaborator server:
java -jar burpsuite_pro.jar --collaborator-server

# Then in Burp → Project Options → Collaborator → "Server location"
# Set to: http://localhost:9090

Step 3: Poll manually

# If automatic polling fails:
# Burp → Collaborator → "Poll now"
# Or check: Project Options → Collaborator → "Polling interval"

Step 4: Check firewall rules

# Collaborator needs:
# - Outbound DNS (UDP 53) to any DNS server
# - Outbound HTTPS (TCP 443) to collaborator subdomains
# - Inbound HTTP (TCP 80) for HTTP interactions

# Test with:
nslookup xyz123.burpcollaborator.net
curl https://xyz123.burpcollaborator.net

Collaborator ready — 3 HTTP interactions retrieved, DNS lookup from target confirmed outbound connectivity.

Prevention

• Test Collaborator connectivity at the start of every engagement.
• For internal network tests, set up a local Collaborator server.
• The out-of-band detection technique is used in Durga Antivirus Pro's network sandbox — isolated environments detect malicious callbacks via Collaborator-style polling.

Common Mistakes with suite collaborator

1. Using head and tail instead of pattern matching, causing runtime errors on empty lists
2. Forgetting that lazy evaluation defers computation until the value is forced, causing space leaks with unevaluated thunks
3. Using return to exit a function early instead of wrapping a pure value in the monad

These mistakes appear frequently in real-world BURP code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ