Network Forensics Part 2: DNS Attacks and Tor Analysis

Professor Talia Q explores advanced network forensics including DNS spoofing attacks, TCP sequence analysis, Tor onion routing, and the challenges of investigating anonymized communications.

Video Creator: Professor Talia Q

Published: 2025-02-27

Tags: Network Forensics DNS Security Tor Analysis TCP Spoofing Dark Web Investigation HarrisonSec

🎬 Overview

This second installment of Professor Talia Q’s forensic series tackles the dark art of network manipulation and anonymity. With practical clarity, He walks us through how attackers exploit DNS, spoof TCP handshakes, and use Tor to hide their infrastructure.

For us at HarrisonSec, this lecture strongly influenced how we approach threat attribution, routing control, and identity assurance in our Secured VLAN architecture.

🧠 Deep Dive: What You’ll Learn

1. DNS Manipulation: The First Layer of Deception

Attackers often use malicious or misconfigured DNS entries to hide real infrastructure.

Talia breaks this down:

  • How DNS works (forward & reverse lookups)
  • How to use dig, nslookup, and whois
  • How fake registrant info and ephemeral domains complicate investigations

➡️ In our VLAN system, DNS egress is tightly controlled. Only one internal proxy has recursive DNS access, and logs are stored with per-VLAN context to reconstruct resolution paths during incident review.

2. Traceroute and Path Attribution

Talia shows how tools like traceroute and VisualRoute can:

  • Identify intermediate routers
  • Map geopolitical routes
  • Detect spoofing via asymmetric paths

➡️ In our enterprise deployments, all DMZ-hosted services are tested using automated traceroute monitors from global probes. This prevents our public surfaces from being sinkholed or redirected silently.

3. TCP Spoofing and Predictable Sequences

This section is gold for protocol analysts:

  • Step-by-step breakdown of the TCP 3-way handshake
  • How spoofing works if attackers can predict sequence numbers
  • Why randomization matters

Talia explains the Robert Morris vulnerability, which relied on non-random initial TCP sequence numbers, allowing connection hijacking or impersonation.

➡️ Inspired by this, our ACL templates block any SYN-only packet from unknown VLANs. We also alert if connections bypass proper state tracking at the firewall.

4. Dynamic IPs + DNS: Hide and Evade

Talia dives into the use of dynamic DNS services (like No-IP) that map constantly changing IPs to persistent hostnames — a common C2 tactic.

➡️ We use passive DNS capture + entropy filtering in our SOC to flag anomalous domain churn, especially in lower-trust VLANs (VoIP, wireless guest).

5. Tor: The Onion Router Explained

The video concludes with a clear, diagram-rich explanation of:

  • Entry nodes, relay nodes, and exit nodes
  • Where traffic is encrypted, and where it’s not
  • Tor’s use for both privacy and abuse

He dispels myths: Tor doesn’t encrypt traffic outside the onion, and browser leaks often reveal IPs anyway.

➡️ While Tor is banned across production VLANs, we allow Tor honeypots in a sandbox VLAN to track attacker behavior — including unsolicited relay probes.

🛠️ Tools Demonstrated

  • dig, nslookup, whois
  • traceroute, VisualRoute
  • Tor, Onion Browser architecture

🔄 How It Powers Secured VLAN Architecture

Everything Talia teaches in Part 2 maps directly to our “Segment + Monitor” philosophy:

Concept VLAN Defense
DNS spoofing Only allow recursive DNS on secured proxy
IP spoofing ACLs reject stateless SYN packets
Tor exit abuse DNS-based denylist + protocol detection
Traceroute inspection Geo-aware egress tracing
Domain entropy abuse Passive DNS + TTL correlation

🧠 Investigator Takeaway

This video isn’t about just theory — it’s about thinking like a threat actor, then designing controls that reduce ambiguity, isolate abuse, and gather attribution.

In short, this video gives you tools that transform your VLANs from blind segments into active, resilient forensic zones.

✅ Final Thoughts

If you build infrastructure… watch this.

If you trace abuse reports… watch this.

If you defend systems where attacks might be invisible to firewalls alone — this lecture is your secret weapon.

➡️ Rewatch it. Bookmark it. Build better systems from it.

Article by: HarrisonSec | Article Published: May 22, 2025
Original Video by: Professor Talia Q | Video Published: 2025-02-27
🎬 Watch Original Video on YouTube