ctf - dom - solution

Here is the solution to CTF ‘dom’ (which has the honour of having to be solved by me just like everyone else, as all the notes taken during creation were misplaced).

dom screenshot

Door photo by Jack Sharp on Unsplash

1

View source and observe the very few resources available.

Page source screenshot

2

Download image.

Curl screenshot

3

Open image using archive utility.

Launching archive utility screenshot

4

Observe new location.txt file and open.

Archive utility screenshot

This required a password, which was a decoded base64 string that had attention drawn to it in the console.

Dev console screenshot

Decoded string ‘usethisaspassword’.

Decoded base64 string screenshot

File contents revealed.

Encoded long base64 string screenshot

<!--Ly8gUGF1bCBTaGFuZSBwZXJmb3JtaW5nICdZb3UndmUgTG9zdCB0aGF0IExvdmluZyBGZWVsaW5nJyAoMTk5Nik= aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj1HUFMwcjNSTWVuYw== Ly8gTG9zdCA1IFNlYXNvbnMgaW4gOCBtaW51dGVz aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj1HZFQ4ZXFNTzRxaw== Ly8gRXZlcnl0aGluZyBCdXQgVGhlIEdpcmwgLSBNaXNzaW5nIC0gKFRvZGQgVGVycnkgUmVtaXgpIChPZmZpY2lhbCBNdXNpYyBWaWRlbyk= aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj1JQWtZNW0wMHJwWQ== Ly8gVGhlIEJsYWNrIEV5ZWQgUGVhcyAtIFdoZXJlIElzIFRoZSBMb3ZlPyAoT2ZmaWNpYWwgTXVzaWMgVmlkZW8p aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj1XcFllZWtRa0FkYw== Ly8gUlVOIERNQywgSmFzb24gTmV2aW5zIC0gSXQncyBMaWtlIFRoYXQgKFZpZGVvKQ== aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj00Ql9VWVlQYi1Haw== Ly8gSW5pIEthbW96ZSAtIEhlcmUgQ29tZXMgVGhlIEhvdHN0ZXBwZXIgKFJlbWl4KSAoVmlkZW8p aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj0xNVVmZk44ZWlsSUx5OGdURzl6ZENBMUlGTmxZWE52Ym5NZ2FXNGdPQ0J0YVc1MWRHVno= Ly9odHRwczovL3d3dy5nb29nbGUuY29tL21hcHMvQDU0LjU0NTY3MjgsLTEuOTM4NzcxMSw1MzY0bS9kYXRhPSEzbTIhMWUzITRiMSE0bTUhM200ITFzMHg0ODdjMjM1Zjk5NGQ4MjMxOjB4YTBlMjM1YTJhYTY2NDM4MiE4bTIhM2Q1NC41NDUyODQhNGQtMS45MjM3NDE=-->

5

Decode Base64 string.

Decoded base64 strings screenshot

<!--// Paul Shane performing 'You've Lost that Loving Feeling' (1996) https://www.youtube.com/watch?v=GPS0r3RMenc // Lost 5 Seasons in 8 minutes https://www.youtube.com/watch?v=GdT8eqMO4qk // Everything But The Girl - Missing - (Todd Terry Remix) (Official Music Video) https://www.youtube.com/watch?v=IAkY5m00rpY // The Black Eyed Peas - Where Is The Love? (Official Music Video) https://www.youtube.com/watch?v=WpYeekQkAdc // RUN DMC, Jason Nevins - It's Like That (Video) https://www.youtube.com/watch?v=4B_UYYPb-Gk // Ini Kamoze - Here Comes The Hotstepper (Remix) (Video) https://www.youtube.com/watch?v=15UffN8eilILy8gTG9zdCA1IFNlYXNvbnMgaW4gOCBtaW51dGVz //https://www.google.com/maps/@54.5456728,-1.9387711,5364m/data=!3m2!1e3!4b1!4m5!3m4!1s0x487c235f994d8231:0xa0e235a2aa664382!8m2!3d54.545284!4d-1.923741-->

Youtube screenshot of Lost 5 seasons in 8 minutes

6

Location revealed!
Barnard Castle

This may have been written at peak ‘Dominic Cummings goes to Barnard Castle’.

Web browser Google Maps screenshot

7

Solution - the distance required.
The distance from Rhyl to Barnard Castle via the M6 is 169 miles.

Web browser Google Maps screenshot showing distance of route to final destination

Conclusion

There was a lot of Base64 in here and it was very CTF-like, but it was thrown together quickly to capitalise on a news event so I make no apologies.

Written on September 1, 2021