PicoCTF2018 - Forensics - What's My Name?

PicoCTF2018 - Forensics - What's My Name?

Objective:

Say my name, say my name [1] .

Hints:

(1) If you visited a website at an IP address, how does it know the name of the domain?

Solution

so the hint is point us to DNS, since that is the service that translates names to ip

so I just filtered the pcap for DNS There are only two DNS packets in the capture
the first is a a query to dns to find out the ip for thisismyname.com

55 1418.342859 192.168.2.12 192.168.2.1 DNS 316 Standard query response 0xaaa0 ANY thisismyname.com A 192.168.2.13 CNAME myname.com MX 5 myname.com MX 10 mx2.myname.com MX 20 mx3.myname.com NS ns1.myname.com NS ns2.myname.com TXT SOA ns1.thisismyname.com

The second is the server's response

here is the result of following the UDP

... .........thisismyname.com.......)............... .....thisismyname.com..............,.....
.........,. .myname...........,.....>.........,...
.mx2.>.........,.....mx3.>........Q....ns1.>........Q....ns2.>.........,.76picoCTF{w4lt3r_wh1t3_2d6d3c6c75aa3be7f42debed8ad16e3b}........Q.. .ns1...dns..[An>......*0..Q.....

picoCTF{w4lt3r_wh1t3_2d6d3c6c75aa3be7f42debed8ad16e3b}

Comments

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