No Start Where - HackTheBox Challenge Writeup

Challenge Information

Field	Value
Challenge Name	No Start Where
Category	Forensics
Difficulty	Medium
Author	d3vn0mi

Description

As echoes of the Dark War lingered in UNZ’s cyber-warfare HQ, a beacon blinked ominously. An analyst turned a wary eye to the screen. The alarm signal originated from the main system that controls the mining machinery! It was an attack from the Board of Arodor, aimed at crippling the mining infrastructure. Initial investigation of the network traffic revealed that the system has been compromised! Your task is to disinfect the system by uncovering the infiltration method and potential post-exploitation steps!

In this forensic challenge, we’re tasked with analyzing a compromised system to determine how attackers gained access and what post-exploitation activities they performed.

Solution Overview

This is a network forensics challenge that requires analyzing traffic captures and system artifacts to identify the attack vector and subsequent malicious activity.

Approach

The challenge requires a methodical forensic investigation:

1. Obtain Challenge Files - Download the provided forensic artifacts (typically a PCAP file or disk image)

2. Initial Triage - Examine what artifacts are available for analysis

3. Traffic Analysis - If a PCAP is provided:

   # Open the packet capture in Wireshark
   wireshark -r traffic.pcap
   
   # Or use tshark for command-line analysis
   tshark -r traffic.pcap -Y "http" -T fields -e ip.src -e ip.dst -e http.request.uri

4. Identify Exploitation Method - Look for:

   • Suspicious HTTP requests or payloads
   • Unusual port connections
   • Command injection attempts
   • Exploit-related traffic patterns

5. Track Post-Exploitation Activity - Analyze:

   • Reverse shells or data exfiltration
   • Command execution logs
   • File transfer patterns
   • Network reconnaissance traffic

Key Steps

Step 1: Analyze Network Traffic

Examine the packet capture for indicators of compromise and exploitation attempts.

Step 2: Identify Attack Vector

Determine the initial access method used by the Board of Arodor attackers.

Step 3: Track Post-Exploitation

Follow the attacker’s lateral movement and data gathering activities.

Step 4: Extract Evidence

Document the flag(s) related to:

• The infiltration method
• Post-exploitation commands or activity
• System compromise indicators

Tools Used

• Wireshark - GUI packet analysis and visualization
• tshark - Command-line packet analysis
• strings - Extract readable strings from binary data
• grep/awk - Pattern matching and text processing
• tcpdump - Alternative packet capture analysis

Key Learnings

1. Network Forensics Fundamentals - Packet analysis is crucial for understanding attack progression in real-time

2. Attack Chain Recognition - Forensic investigations reveal the complete attack lifecycle from initial access through post-exploitation

3. Evidence Preservation - Understanding traffic patterns helps reconstruct exactly what an attacker did on a compromised system

4. Payload Analysis - Recognizing exploit patterns and malicious payloads in network traffic

5. Timeline Construction - Using packet timestamps to build a chronological narrative of the attack

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Note: The solve checkpoint indicates this challenge requires hands-on analysis of provided forensic artifacts. The specific flag format and detailed solution steps depend on the actual challenge files provided at runtime. Focus on systematic packet analysis and artifact examination to uncover the infiltration method and post-exploitation activities.