US Cyber Games
This was my first year competing in the US Cyber Games. I focused on forensics because I am pretty strong with wireshark and enjoy the puzzle solving aspect of it.
US Cyber Games 2024
US Cyber Open 2024 Writeups
Forensics: Redundant
- Given a "corrupted" PNG file
- Examine magic bytes w/ CyberChef and gHex
-
Run through go-to stenography tools:
- binwalk -ef
- Digital Invisible Ink Toolkit
- Steghide
- CyberChef
- Reread prompt and notice "corrupted" is emphasized
- Open file in online PNG repair tool to find flag
Forensics: Tubes
- Notice challege name is a play on Senator Ted Stevens' "series of tubes" speech
- Connect to linux box w/ netcat
-
Run through go-to commands to look at network traffic/connections
- netstat
- tcpdump
-
Filter out ssh noise in tcpdump:
tcpdump not port 22 - Notice strange | and \ characters in UDP traffic
-
Filter UDP traffic in tcpdump:
tcpdump -A 'udp'and found flag
Forensics: Timing is Everything
- Given a pcap file
- Open in Wireshark
- Notice the 2nd timestamp is 0.8300 which happens to be S in ASCII
- With a little bit of bruteforcing the flag format, notice that the timestamps are incremented in the ASCII codes for the flag
- Calculate flag by converting timestamp differences to ASCII