Solution Steps

1. Download the PCAP file from the challenge page.
2. Open the file in Wireshark and begin your analysis:
   • First, look for DNS queries containing 'flag_' in the subdomain
   • Then, look for ICMP packets containing 'FLAG_PART:' in the payload
   • Finally, look for HTTP requests containing 'FLAG:' in the headers
3. To find the flag in DNS queries:
   • In Wireshark, use the filter: dns and dns.qry.name contains "flag_"
   • Look at the 'Query' field in each DNS packet
   • The flag parts are in the subdomains after 'flag_'
   • For example, if you see 'flag_123.abc.lab.hdna.me', '123' is part of the flag
4. To find the flag in ICMP packets:
   • In Wireshark, use the filter: icmp
   • Look for packets with 'FLAG_PART:' in the data
   • The flag parts are after 'FLAG_PART:'
   • For example, if you see 'FLAG_PART: 456', '456' is part of the flag
5. To find the flag in HTTP traffic:
   • In Wireshark, use the filter: http
   • Look for HTTP requests with 'FLAG:' in the headers
   • The flag parts are after 'FLAG:'
   • For example, if you see 'FLAG: 789', '789' is part of the flag
6. Combine all the flag parts in order to form the complete UUID flag.
7. Submit the complete flag on the challenge page.

Example

If you find these parts:

• DNS: flag_123.abc.lab.hdna.me
• ICMP: FLAG_PART: 456
• HTTP: FLAG: 789

And they appear in that order in the traffic, the flag would be: 123456789

Key Points

• The flag is a UUID split into parts
• Each part is hidden in a different protocol
• Look for the specific markers: 'flag_', 'FLAG_PART:', and 'FLAG:'
• The parts appear in the correct order in the traffic