GeoSINT CTF — Long Way

Challenge: https://geosint.ctf.uz/2807ffe8-e563-4972-9c94-087e9adf67ca
Hint: “On the way to Black Hat MEA”
Status: Solved and verified

Objective

Identify the exact road position from a desert photograph containing power lines and almost no conventional landmarks.

Step 1 — Extracting metadata

Unlike many GeoINT images, the original file retained useful EXIF data even though GPS was absent:

Camera:           iPhone 15
DateTimeOriginal: 2025:12:03 10:47:37
Time zone:        +03:00
iOS:              18.3.2
GPS:              absent

The timestamp was crucial. Black Hat MEA 2025 was held from 2–4 December 2025 at the Riyadh Exhibition & Convention Center in Malham, Saudi Arabia. The photograph was therefore taken during the event window and in the local Saudi time zone.

Step 2 — Interpreting “on the way”

The hint described a journey rather than the venue itself. Event transport information indicated shuttle departures from the SAB Metro station area toward the Malham venue. A route between those points runs north from Riyadh along the King Fahd / Al Qassim highway corridor.

This matched the photograph:

• arid, open terrain;
• a divided high-speed road;
• a yellow edge line viewed through a vehicle window;
• repeated guyed utility poles and multiple parallel distribution lines;
• no dense urban development.

Step 3 — Matching the utility corridor

The road route alone was too long to guess safely. OpenStreetMap geometry was used to compare the route with nearby power infrastructure. The useful discriminator was a tight cluster of three minor power lines crossing or running immediately beside the highway.

Projecting that cluster onto the driving route isolated a point near:

25.086832, 46.481893

This is on King Fahd Road / Highway 65 in Huraymila Governorate, Riyadh Province, north of Riyadh and south of the Malham event venue.

Verification

The narrowed candidate was submitted to the task-specific verifier and was accepted:

{
  "status": "correct",
  "flag": "CTF.UZ{y3s_it_w4s_a_v3ry_l0ng_w4y}"
}

Result

• Location: King Fahd Road / Highway 65, Huraymila Governorate, Riyadh Province, Saudi Arabia
• Coordinates: 25.086832, 46.481893
• Verifier result: status: correct
• Flag: CTF.UZ{y3s_it_w4s_a_v3ry_l0ng_w4y}

Map: https://www.openstreetmap.org/?mlat=25.086832&mlon=46.481893#map=17/25.086832/46.481893

References

• Black Hat upcoming-events page: https://www.blackhat.com/upcoming.html?meevents=
• Black Hat MEA FAQ: https://blackhatmea.com/faq
• Event transport document: https://www.linkedin.com/posts/blackhatmea_how-to-get-to-black-hat-mea-2025pdf-activity-7401500550854410241-2NNM

Lessons learned

1. Always inspect EXIF before beginning visual research; a timestamp can be as valuable as GPS.
2. Interpret travel hints as a route problem, not merely a destination clue.
3. When the scene lacks landmarks, combine road geometry with secondary infrastructure such as power-line crossings.
4. Submit only after independent clues converge, then preserve the verifier response as proof.