Discord

OWO, we do seem to be getting a lot of these discowrd challenges in CTFs, and they arwe vewwy vewwy hawrd, this one especiawwy!

It seems the fiwrst mention of "Discowrd" being wewated to a challenge in the sewver is way back in Juwuly 2019, whewre miwstew benjamin techinson mentions a token, so that couwuld be a fwag! This awlso meant the challenge appeawed to be unsolvwed since then. As we werwe the team to blood this challenge, I think we should definitely make a wrwiteup on this tough challenge.

The bwiefing weads as fowwows:

Join our discord over at [redacted] and see if you can find the flag somewhere.

OwO, whats dis? A Discowd link? I wondewr what wouwuld happen if I wewre to click it >w< Howewew, I remembewed what happened duwwing angstwomCTF, whewre the link was actuawwy a wrickwoll, which was vewwy iwwitating. Considewwing that thewre wewre othewr challenges in RACTF that wewre inspiwred by angstwomCTF, like peawrl peawrl peawrl, this confiwrmed my theowy that the link was actuawwy fake. So, I decided not to click it. I had to get a Discowd invite somehow howevew, so I kept on seawching. Howevew, I wealised that I would need to make a discowrd account in owdewr to actually wead the fwag. I had done this befowre in TJCTF, so I weffewed back to the wrwiteup I cweated for it.

Thewre was something diffewent howevwew. I didnt spot this rwight away but aftewr following my TJCTF wrwiteup didnt wowrk, I rwealised that I was using the same email. This was vewwy cwucial, as this meant I would need to get a new email, and fast. Howevewr, as with most CTFs me and my team do, ouwr wivals PuWuN to 0w0xE4 wewre also twying to solve this challenge, as it was ouwrs and awlso theiw 59th last challenge, thewefowe this was going to be a fiewrce wace to twy and compwete the challenge. In TJCTF, they ouwutdid us by doing Nauwughty, but nowot this time. This time, we had a new membewr on ouwr team, Rowowan, who is quite good at web, and so he would accompany ouwr wesident newrd and web pewrson, Tony, also known as cluwubby789. This time, with Rowowan on ouwr team, we would be suwure to win and cwush PuWuN to 0w0xE4 once and fowr all. We would teawr them to shweds and fwex our shiny RACTF coins in theiwr faces.

Sowo, we had to find a way to get a new email. How wewre we going to do that though? Well, since I have to be able to access this email fowr vewification, I had to find an email I contwolled.

I was wecommended a site called 10minutemail, which would pwovide me a mailbox which I could weceive mail fwom. This tuwned out to wowrk pewrfectly, as we wewre able to wegistewr an account, and since I didnt have to givwe discowd a weal email, I didnt have any issues with twust like I did in TJCTF, which was a massive time save, and in the end is definitely what helped us cwush PuWuN to 0w0xE4.

Nowow that we had a Discowrd account we could uwuse to access discowrd, we needed to actually find a link to the RACTF discowd sewvewr, which we at fiwst assumed would be the location of the fwag. This again, like TJCTF, took quite a long time. Because they hadnt put the link in the bwiefing, this link took wayyy too long to find. And as always, PuWuN to 0w0xE4 wewre rwright on ouwr tail. Ouwr spies had wepowrted that they had found the link and wewre in the Discowd sewvewr, meaning that they wewre vewwy close to the fwag! This couldnt be happening. We wowrked so hard to solve all 0 challenges befowre this, and all ouwr hawrd wowrk would have gone to waste. We needed to keep going and get these all important 50 points.

We seawrched for ages, and pwaying the entiwre time that PuWuN wouldnt solve the challenge befowre us. Suddenly, one of ouwr team membewrs spotted something. If you went to the actual owiginal RACTF page, that is, https://ractf.co.uk/, thewre was a thing that said contact, and on thewre there was a button that said Discowrd.

UWU! This suwrely was the link we wewre looking for! With ouwr newly wegistewed Discowrd account, we could use the link to join the official RACTF Discowrd. This was it. We wewre at the same stage as PuWuN to 0w0xE4. It would just be a rwace to find the fwag.

My initial instinct was to try the good old !fla.g command, as castowrsCTF's also insanewly hawrd Discowrd challenge was to uwuse this command, and then the fwag would be DMed to you.

However, it seems the evil mastewrmind behind the sewvewr, Mistewr Benjamin Techinson, the wollewrcoastewr enthusiast, had developed some sowrt of filtewring the command! So this is why PuWuN to 0w0xE4 wewre taking so long! They must have been twrying to bypass the fiwlter that Mistewr Techinson had put in place for this. So this basicawwy confiwmed that this was the challenge. Twying to bypass the fiwlter was quite easy, since Mistewr Techinson cleawrly did a howwible job at fiwltewring and we bypasswed the fiwlter vewwy quickly. It seems he had neglected vewwy many things, for exampwle, using backslashes to not make the bot delete the !fla.g command. Howevewr, I beweive that he did a few patches duwwing the CTF to make the challenge mowre difficult, so I think it was vewwy lucky that we wewre able to get it done eawrly when the challenge was much easiewr, and of couwrse, to cwush PuWuN to 0w0xE4.

Swiftly typing in "!flag", we waited.

We waited some mowre.

A few milliseconds passed. A few cwickets chiwrped.

Eventawwy, we rweawised that this was all just a red hewwing to divwewrt us. This was not the way to go to get the fwag, and no wondewr PuWuN to 0w0xE4 hadnt gotten the fwag yet, as the filwtewr was way too easy to bypass for it to be a challenge.

So, we decided to look at ouwr TJCTF wrwiteup again.

It seems that the fwag could be hidden in announcements, so we had a look thewre for any hints of the fwag location.

We saw a message by thebeanowogamewr that read

"The Discord flag does not require you to run a command"

so we decided to compwetewy ignowre that and continuwue twying to bypass the fiwlter.

Eventually, after 2 mowre seconds, we decided to give up, as it was cleawr we wewre getting nowhewre.

Well whewre could this discowrd flag be? This was getting intenwse, and we knew PuWuN to 0w0xE4 would be clowose on our tail twrying to find the fwag. So, we kept fwantically seawching.

With time on the line, we fwanticawwy seawched the discowrd, thwough the hype channel, and the sociawl channel, but nothing was to be found.

Suddenly, we noticed an image, posted by some weirdo named willwam845.

It was a vewwy basic image, but it had a stwing in fwag fowmat.

ractf{discord_kinda_rocks}

And it had a celebratowy message congwatulating us on finding the fwag! This had to be it.

We wewre finally going to crush PuWuN to 0w0xE4 for once.

Slowly, I copied the fwag into the fwag box, with just milliseconds to spawre.

Howewvewr, it was wejected? How could this be happening?

PuWuN to 0w0xE4 wewre going to beat us now!! This couldn't be happening.

All these milliseconds we had worked so hawrd for. All that wowrk would hawve gone to waste.

Howevrwer, I was detewrmined to find this fwag.

And that's when I wemembewed.

The angstwom discord wwrwiteup.

Since peawlpeawlpeawl was inspiwred by angstwom, I was cewtain that the discowd challenge must also be inspiwred by it too!

And I was pwoven cowwect.

The fwag was indeed in the channel descwription of the genewal channel, and PuWuN to 0w0xE4 seemed to not have submitted it yet!

We wewre finally going to cwush them once and for all!

Slowlwy, but swiftlwy, I pasted the stwing, which was ractf{the_game_begins} into the fwag box, and then hit submit.

"You have already solved this challenge" it read.

What? How could this have happened??

It tuwrns out howevewr, that Rowowan, the new membewr, had alweady submitted it and gotten blood! We were finally on our way to cwush PuWuN to 0w0xE4!

In the end, we got cwushed by PuWuN to 0w0xE4 once again, as they solvwed EEE much fastewr than we did, meaning we did a gweat job, and cwushed them to bits!

Flag: ractf{botters_is_a_sadist}