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idekCTF 2022* – NMPZ

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    Exceedingly extra writeup guy
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We recently played idekCTF 2022* (with an asterisk... because it’s 2023), an extraordinarily “race against the clock”-esque CTF with a ridiculously large pool of challenges—58 of them, over a 48-hour runtime. We managed to snag a 1st place finish after countless hours of not touching grass (despite analyzing it throughout this challenge), and I would like to share my personal favorite OSINT challenge of the competition—“NMPZ”, an acronym in the GeoGuessr community for “no moving, panning, or zooming.” Although we hadn’t 100% correctly solved the challenge (we inferred part of the flag), here was our thought process tackling it. Enjoy!


NMPZ

Are you as good as Rainbolt at GeoGuessr? Prove your skills by geo-guessing these 17 countries.

Attachments: nmpz.zip

The provided README file contains the following:

Figure out in which country each image was taken.
The first letter of every country’s name will create the flag.
Countries with over 10 million inhabitants will have a capital letter.
Countries with less than one million inhabitants become an underscore.

Here is a table of the provided example flag (idek{TEST_flAg}), and how the flag construction works:

ImageCountry of OriginPopulationFlag
1.pngtrTurkey84,680,273 (2021)T
2.pngecEcuador18,145,568 (2023)E
3.pngesSpain47,615,034 (2022)S
4.pngthThailand66,883,467 (2023)T
5.pngvaVatican City825 (2019)_
6.pngfiFinland5,528,796 (2022)f
7.pngltLithuania2,839,020 (2022)l
8.pngarArgentina47,327,407 (2022)A
9.pnggeGeorgia3,688,600 (2022)g

We’re given... 17 different screenshots of locations on Google Street View. Currently, our goal is to find the country of origin for each and every single one of these screenshots, and to combine each letter together to form the flag (as per the README). Let’s get to work.


1.png

Picture of a waterfront walkway near a sea, with boats in a local harbor with overcast skies. A small statue is visible in the background, peeking above the clouds

Looks like we’re on a waterfront walkway with a beautiful view of a harbor. A quick Google Lens results in a “Muerta da Urca” in Rio de Janeiro, brBrazil:

Google Lens output for 1.png

Oh, yeah, there’s totally a World Wonder in the background by the way... Christ the Redeemer:

Zoomed in picture of Christ the Redeemer in the background

Since Brazil had a population of ~215 million in 2022, it’ll be capitalized in the flag. For brevity’s sake, I’ll be omitting the populations from here on out—however, I’ll still include them (alongside sources) in the upcoming progress tables.

Trivial! 1/17 down.

Flag Progress: idek{B________________}


2.png

Picture of a flat plaza with Cyrillic posters on the left side. There is a Russian-style Orthodox church in the background

Wow... this is the most ruRussia photo I’ve ever seen! If you don’t believe me, here’s a Google Lens of the very evident St. Basil’s Cathedral looming in the background:

Google lens output of 2.png

Flag Progress: idek{BR_______________}


3.png

Picture of an empty sidewalk in a European business district. There is a lamppost in the center-left of the screen with directional signs on it

Finally, no more trivial landmarks in the background! Looks like we’re now on the roadside of some European business-y area. I quickly noticed a name on the brown sign attached to the streetlight:

Zoomed in picture of the directional signs on the lamppost

It reads “Kalamaja”, which upon a quick Google results in a small city district in Tallinn, eeEstonia:

Google search results for the term “Kalamaja”

Flag Progress: idek{BRe______________}


4.png

Picture of the side of a rural highway, with patchy grass and reddish soil

The middle of nowhere... a classic. Let’s see what the Google Lens yields:

Google Lens output of 4.png

The first result identifies a Stuart Highway, which runs straight through central auAustralia (a.k.a. the middle of nowhere). Also, if you look closely, there’s a reflector sign in the center of the photo which looks exactly like the Australian bollard on geohints.com, a resource for GeoGuessr players:

Zoomed in picture of the bollard at the center-bottom of `4.png`

Bollard in 4.png

Screenshot of example Australian bollards on geohints.com

Australian bollard in geohints.com

Additionally, a key “Australian” identifier would be the orangey dirt on the roadsides, which is common around the country.

Flag Progress: idek{BReA_____________}


5.png

Picture taken on top of a car in a small, dusty alleyway. There is Arabic script on the right-hand side, and the license plates are yellow. Left-hand drive is also present

This one was extraordinarily rough. According to the author themselves:

its hilarious that every single person got one country wrong, but the letter was the same so it didnt matter... you included ;)
— jazzzooo

...and apparently this was the one that everyone was messing up!

Let’s move on to my approach. I noticed a few things:

Labeled version of 5.png
  1. The extraordinarily ambiguous “Third St” on top of the grey SUV in front of us
  2. The words “Al-Siraad Plaza” plastered to the side of the grey building on the left
  3. The words “Ab-Furqan” on the poster above the white/green checkered wall on the left
  4. Arabic script on the walls of the white/green building on the right
  5. An advertisement for “Peri Peri Pizza” on the far right
  6. Consistently yellow license plates

All signs point to an Arabic-speaking country. In addition, since we solved each image out of order (and knew the next character would be an underscore) the flag contained the word segment BReA-, which only had three possibilities to form a proper word: BReAD, BReAK, and BReAM (which we ruled out due to unlikeliness). As a result, we simply guessed the country to be kzKazakhstan (even though it doesn’t have official Google Street View coverage and Arabic isn’t a nationally recognized language).

GeoGuessr Meta: The Infamous Snorkel

Now... here is the absolutely crazy part. After solving the challenge, the author revealed to me what the actual country was:

do you see the little snorkel on the right front corner of your car in 5.png? i implore you to google “geoguessr snorkel” haha
— jazzzooo

I had no idea what they were talking about, so I zoomed in on the car and lo and behold, snorkel:

Zoomed in picture of the “snorkel”-looking object (an upward exhaust) on the car’s right-hand side

I did a quick Google search, and found a tweet from the official GeoGuessr Twitter account:

Tweet not found

The embedded tweet could not be found…

Apparently, this was one of the strategies that GeoGuessr pros use to quickly identify countries: using the car the Photo Sphere was taken from to their advantage, considered to be part of the “meta” game. The “ke Kenya Snorkel” was one of the more infamous ones, and I had no idea it existed. I was absolutely blown away.

Flag Progress: idek{BReAK____________}


6.png

Picture of a road in an extremely flat & empty plains, with overcast skies and yellow reflector poles

Ah, yes, another “middle of nowhere.” This time, however, it’s a bit easier! Here’s the Google Lens yield:

Google Lens output of 6.png

Yep, that’s definitely isIceland. Here are some things you use to identify Iceland:

  • 99% of the time there will be overcast skies
  • Off-green, almost yellow-ish grass. Here is an example from GeoHints:
Example screenshots of Iceland on geohints.com
  • Bollards! These ones are bright yellow with a diagonally pointed top, and a white reflector:
Screenshot of yellow bollard in `6.png`

Bollard in 6.png

Screenshot of example Icelandic bollards on geohints.com

Icelandic bollard in geohints.com

This character will be an underscore (_), since the population of Iceland is 376,000 (2022).

Flag Progress: idek{BReAK____________}


7.png

Picture of a giant neighborhood in a brushland/desert region, with wooden fences, roofs, and electric poles

Wow... I’ve never seen a neighborhood this massive with not a single piece of foliage in sight. Here’s the Google Lens output:

Google lens output of 7.png

Definitely Ulaanbaatar, mnMongolia! We confirmed it with the license plate of the car on the left:

Zoomed in screenshot of a car’s license plate in `7.png`

License plate in 7.png

Wikimedia Commons example of Mongolian license plate

Mongolian license plate ( Wikipedia)

Flag Progress: idek{BReAK_m__________}


8.png

Picture of a hilly region with paved roads and scarce foliage. The houses have red-tiled roofs

This was arguably one of the hardest to solve (and one that we got incorrect). Here’s the Google Lens output:

Google Lens output of 8.png

No idea! Our original guess was the phPhilippines or idIndonesia, but BReAK_m(P/I)_ didn’t make any sense. We moved on to the next image and discovered it was an underscore (_), and eventually came to the conclusion that the country had to either start with E or Y to make any sense (to make either BReAK_m(Y/y) or BReAK_m(E/e)). The only recognized country which starts with Y is yeYemen, which was an unlikely guess because of the consistent greenery, foliage, and hills (in the Arabian Peninsula, practically all desert).

In accordance with E/e as the only likely character, we eventually settled on either svEl Salvador or ecEcuador, so this character would be either uppercase or lowercase.

Flag Progress: idek{BReAK_m(E/e)_________}


9.png

Picture taken in the water off the shore of a large city’s downtown area. The buildings are mostly white and there are hills in the background

A Photo Sphere in the middle of the sea! Looks like we’re in a pretty large city, and it’s giving off tourist resort-y vibes. Here’s the Google Lens output:

Google Lens output of 9.png

It looks like it’s identified the cityscape as belonging to mcMonaco. It’s even identified the facade of one of the buildings in the city as the Opéra de Monte-Carlo:

Zoomed in picture of grand building in the city skyline

Let’s add an underscore to the flag, since Monaco’s population is 37,308 (2016).

Flag Progress: idek{BReAK_m(E/e)_________}


10.png

Picture of a small town next to a hillside, with North European/Scandinavian-style houses

We’re now given a small town in the hills of an assumingly European country (overall house aesthetic). Here’s the Google Lens output:

Google Lens output of 10.png

Lens results are giving me either chSwitzerland or noNorway. My suspicions for Switzerland were confirmed when I saw its recognizable square flag hanging off one of the houses:

Zoomed in picture of the Swiss flag hung off the eave of a house on the left

Flag Progress: idek{BReAK_m(E/e)_s_______}


11.png

Picture of a sparsely green suburban neighborhood, with not many houses

Splat in the middle of an inconspicuous-looking suburb! Here’s the Google Lens output when you focus in on the bollards on the street (since there’s nothing of interest anywhere else):

Google Lens output of 11.png

Scrolling through the outputs results in distinctly plPolish bollards:

Zoomed in picture of a bollard in `11.png`

Bollard in 11.png

Screenshot of example Polish bollard on geohints.com

Polish bollard in geohints.com

Flag Progress: idek{BReAK_m(E/e)_sP______}


12.png

Picture of a distinctly European street curving right with business establishments on the left-hand side

More Europe! Here’s the Google Lens output:

Google Lens output of 12.png

The vertical sign reads “ELEKTRO”, whilst the lower horizontal sign reads “Weißensteiner”, two distinctly German words (with the latter being a surname, romanized into “Weissensteiner”). Although we could automatically assume deGermany, there are multiple other German-speaking European countries, so we’ll have to narrow it down further.

Here’s the solution: simply Google “Elektro Weißensteiner” and you’ll find that it’s an electronics store based in atAustria:

Google search result of “Elektro Weißensteiner”

Elektro Weißensteiner GmbH
4.3 ⭐⭐⭐⭐⭐ 6 Google reviews
Electronics store in Liezen, Austria

Flag Progress: idek{BReAK_m(E/e)_sPa_____}


Pit Stop

We’ve now come to a completely arbitrary stopping point—from here on out, each .png will become exponentially harder... so let’s just recap what we’ve gotten so far. Note that incorrect countries will be italicized:

ImageCountry of OriginPopulationFlag
1.pngbrBrazil215,652,035 (2023)B
2.pngruRussia146,980,061 (2022)R
3.pngeeEstonia1,331,796 (2022)e
4.pngauAustralia26,033,493 (2023)A
5.pngkzKazakhstan19,392,112 (2023)K
6.pngisIceland385,230 (2022)_
7.pngmnMongolia3,477,605 (2023)m
8.pngsvEl Salvador / ecEcuador6,825,935 (2021) / 18,145,568 (2023)e/E
9.pngmcMonaco39,150 (2021)_
10.pngchSwitzerland8,789,726 (2022)s
11.pngplPoland37,796,000 (2022)P
12.pngatAustria9,090,868 (2022)a

Let’s proceed with the rest of this challenge.


13.png

Picture of a paved road spanning an extremely flat area covered with dead prairie grass

This is probably the quintessential “North America” picture ever—impossibly flat land, a random city skyline in the background, and huge fields. A Google Lens search yields nothing we don’t already know:

Google Lens output of 13.png

Currently, our only issue here is telling between either caCanada or the usUnited States. Let’s narrow it down a bit more.

The only telling sign here is road markings. Since I live in the US, I know that two-way roads (with one lane per direction) are typically marked with either broken double yellow lines or solid double yellow lines. Although single dashed yellow lines exist in the US, they are much more common in Canada (albeit still existing in the US). Here’s a diagram I threw up, which you can combine with the overall “feel” of an image to make a calculated guess:

Original diagram of American vs. Canadian road markings. “Either US or Canada” is labeled for both broken/solid double lines, while “More likely Canada” is marked for single dashed lines

Alongside this, not a single common word in English starts with the prefix spau-, so ruling out the US is a no-brainer. However, the above knowledge about road markings is useful when you have no flag to infer characters from!

Flag Progress: idek{BReAK_m(E/e)_sPaC____}


14.png

Picture of a roadside in a seemingly tropical area. There are black on yellow turn chevrons on the edges of the road, and a car off to the right with an orange license plate

This one was actually really, really clever. Although a Google Lens yields nothing of use (since its viewpoint is a random tropical area), take a look at the bottom right-hand corner of the image:

Screenshot of the street label partially visible on the bottom right of the image

Is that an acute accent mark on top of the letter I (“í”)? Inferring from the shape of the other letters, it looks like this segment of the word spells out “-íal”, which many Spanish words end with. We can safely narrow this down to a Latin-American/Spanish-speaking country.

Let’s keep inferring from the flag. It currently says BReAK_m(E/e)_sPaC, so we can safely guess that the next country should start with “e” or “E” to continue the next likely word, “space.” ecEcuador and svEl Salvador are the only Spanish-speaking countries that start with “e” or “E”, and I was able to narrow it down to Ecuador solely from the license plate of the car on the right, which looks like a taxi:

Zoomed in picture of blurred orange license plate

License plate in 14.png

Wikimedia Commons example Ecuadorian license plate, colored orange to indicate taxis/buses

Ecuadorian license plate (commercial vehicles, Wikipedia)

Flag Progress: idek{BReAK_mE/e_sPaCE___}


15.png

Picture of a dilapidated, bleak snowy area with a dirt road weaving through two red-tiled houses. A small metal dumpster rests on the left

We are now presented with... some dilapidated, snowy houses! This will be difficult to narrow down.

Google Lens yielded nothing of use, but I did identify some Cyrillic writing on the dumpster to the left:

Zoomed in picture of dumpster with Cyrillic writing

The Guesswork Begins

This was around the time my team started to suspect the flag for the challenge read “break me spacebar”, which is a meme in the GeoGuessr community for how content creator Rainbolt hits his spacebar really loudly when guessing a location on the map:

Google search for “rainbolt spacebar”

YouTube: ”1 hour of silence randomly interrupted by Rainbolt annihilating his spacebar” by wid
YouTube: “geoguessr but i have to slam my spacebar” by Toofee
YouTube: “Rainbolt hitting space bar for 1 minute” by PSM

In accordance with the word “spacebar”, I narrowed the country down to the only Russian-speaking country (in terms of officially recognized languages) with starts with “B”: byBelarus.

GeoGuessr Meta: Snow Coverage

So... Belarus was incorrect. However, it had a population under 10 million (similarly to the correct answer), meaning that the letter b was correct, regardless. The real country this image was taken in was bgBulgaria, which a pro player would guess due to the typical snow coverage of Google Street View. According to this GeoGuessr Tips article:

Hungary is one of three European countries that can have similar, bleak, winter scenery with trees without leaves and snowfall beside the road. The other two countries are Bulgaria and small parts of Czechia.

Much of Bulgarian Street View was taken in winter and thus the trees are often without leaves and the Street View scenes in Bulgaria are often fairly bleak. Within Europe, Hungary and parts of Czechia have similar bleak wintery scenery. Bulgaria is one of the poorest countries in Europe and the Bulgarian roads reflect this fact. These roads are commonly crumbling and filled with cracks and holes.

So when you see a combination of dilapidation/bleakness and snowiness, Bulgaria, huHungary, or czCzechia would be your best guesses.

Flag Progress: idek{BReAK_m(E/e)_sPaCEb__}


16.png

Picture of a beautiful valley area with hills and mountains, and a white on black turn chevron on the road

Beautiful hills and mountains... However, I genuinely have no idea where this could be!

Let’s start off with what little we have, and analyze the black and white chevron marker in the center of the image:

Zoomed in picture of the turn chevron

I initially scoured the internet for countries which use this specific chevron and came across this map, courtesy of user u/isaacSW on the r/geoguessr subreddit:

Diagram of Europe, with each country filled in with the color of turn chevrons they use

According to this map, the only countries which use white-on-black turn chevrons are the gbUnited Kingdom, chSwitzerland, itItaly, grGreece, alAlbania, and occasionally esSpain.

Since this part of the flag says “spacebar”, the only choice which starts with “A” is Albania, so we will be using “a” for this character.

GeoGuessr Meta: Rifts in the Sky

After the challenge was completed, the author revealed something really interesting about this image... “rifts in the sky”:

Apparently, for countries like Albania, meMontenegro, and snSenegal, there are camera imperfections in the Photo Sphere which result in creases in the sky:

Various screenshots on geohints.com of rifts in the sky

We can see the rift itself in 16.png in the top center of the image:

Screenshot of the image imperfection in the center-top section of 16.png

Little meta tricks and trivia like these are what make GeoGuessr such an interesting game.

Flag Progress: idek{BReAK_m(E/e)_sPaCEba_}


17.png

Image of dilapidated sheds and fences next to an ocean, with overcast skies

To be honest, we didn’t solve this one at all—we just completed the sentence “break me spacebar” and guessed the last character was either “R” or “r”. Our original khCambodia guess didn’t make any sense, anyways :P

GeoGuessr Meta: The Sakhalin Plant

The author of the challenge revealed that the last location was ruRussia, on the large island of Sakhalin north of jpJapan:

Screenshot of Google Maps with red circle around Sakhalin Island

The intended method of identifying the location was to analyze this patch of particular foliage in the image:

Zoomed in picture of butterbur in bottom-center of 17.png

This plant is called butterbur (Petasites japonicus, or colloquially “The Sakhalin Plant”), and it’s native to Sakhalin, Japan, cnChina, and kp/kr Korea. Apparently, GeoGuessr pros can instantly identify this particular area of Russia from this plant alone!

Flag Progress: idek{BReAK_m(E/e)_sPaCEbaR}


Afterword

With this, the entire flag is revealed, and was successfully submitted with a lowercase “e” for the eighth character (the country was actually szEswatini); the flag is idek{BReAK_me_sPaCEbaR}.

This challenge would have not been possible if the flag wasn’t made up of recognizable English words. When we were approaching the end, we simply inferred that the last bit spelled “spacebar”—although we could have brute forced all 8 different capitalizations of “bar” (232^3) by the time we finished “sPaCE”, we felt like doing so would have detracted from the fun of the challenge.

Overall, I didn’t just learn more about GEOINT-style challenges—I came to a greater understanding of how absolutely massive Earth is. I guess that’s part of the fun in playing GeoGuessr!

Here is a final table of all the countries (and what I guessed incorrectly):

ImageCorrect CountryPopulationFlagIncorrect Guess
1.pngbrBrazil215,652,035 (2023)B
2.pngruRussia146,980,061 (2022)R
3.pngeeEstonia1,331,796 (2022)e
4.pngauAustralia26,033,493 (2023)A
5.pngkeKenya47,564,296 (2019)KkzKazakhstan
6.pngisIceland385,230 (2022)_
7.pngmnMongolia3,477,605 (2023)m
8.pngszEswatini1,202,000 (2021)esvEl Salvador
9.pngmcMonaco39,150 (2021)_
10.pngchSwitzerland8,789,726 (2022)s
11.pngplPoland37,796,000 (2022)P
12.pngatAustria9,090,868 (2022)a
13.pngcaCanada39,082,640 (2023)C
14.pngecEcuador18,146,244 (2023)E
15.pngbgBulgaria6,520,314 (2021)bbyBelarus
16.pngalAlbania2,829,741 (2021)a
17.pngruRussia146,980,061 (2022)R

Resources

Here are some of the websites I used throughout the challenge-solving process:

  • GeoHints - Provides images and key characteristics of every covered country in Google Street View
  • GeoTips - Lots of meta stuff (e.g. camera quality, cars vs. trekkers, etc.)
  • r/geoguessr - Useful community diagrams and wiki
  • The Digital Labyrinth - GeoGuessr - An absolutely massive blog post with everything you need to know about the game and its tricks
  • World License Plates - Scanned license plates of the majority of countries, including old and new designs
  • Google Lens - A powerful image recognition tool which can identify objects, text, landmarks, foliage, you name it and provide similar images