Walkthrough

Walthrough of HEXA CTF phone triagulation challenge

SO unfortuantely I dont have access to origional text for challenge at this point, however the essence was to find the neighbourhood for a phone that was part of an investigation that was within the CTF storyline

information given was a dialing code 44, which is a UK international dialing code (intrinsic knowledge) and then a snipet of information that the carrier was EE (formally Orange), then a LAC and a Cell ID

Googling cell phone triagulation sites found https://opencellid.org/ as the top site for this

THis site allows you to plug in the data and provides a map reference for nearest cell towers to the site

However it needed MCC and MCN codes, which were not within the information given, or was it!

Another quick search found https://cellidfinder.com/mcc-mnc which shows both of these variables in a list by country and carrier

Looking through you can find that EE (formally Orange) is listed as MCC = 234 and MNC = 33/34

Plugging the varibales back into OpenCellid brings you to https://opencellid.org/#zoom=17&lat=51.487678&lon=-0.16981

Highlighted in the middle of the map is the London neighbourhood of Chelsea

therefore flag was HEXA{chelsea}