Flare On 5

[kao]

The FireEye Labs Advanced Reverse Engineering (FLARE) team’s annual reverse engineering challenge will start at 8:00 p.m. ET on Aug. 24, 2018. 
This is a CTF-style challenge for all active and aspiring reverse engineers, malware analysts, and security professionals. So dust off your 
disassembler, put a new coat of oil on your old debugger, and get your favorite chat client ready to futilely beg your friends for help. 
Once again, this contest is designed for individuals, not teams, and it is a single track of challenges. The contest runs for six full weeks 
and ends at 8:00 p.m. ET on Oct. 5, 2018.

This year’s contest will once again host a total of 12 challenges covering architectures from x86, x64 on Windows, Java, .NET, Webassembly, 
and Linux, with special appearances of Bootloaders and Bootkits. This is one of the only Windows-centric CTF challenges out there and we have 
crafted it to represent the skills and challenges of our workload on the FLARE team.

If you complete the Flare-On Challenge you will receive a prize and permanent recognition on the flare-on.com website for your accomplishment. 
Prize details will be revealed when the contest ends, but as always, it will be something that will be coveted and envied by your peers. In 
prior years we’ve had rodeo belt buckles, replica police badges, challenge coins, and a huge pin.

Check out the Flare-On website for a live countdown timer and to see the previous year’s winners. For official news and support we will be 
using the Twitter hashtag: #flareon5.

9 days left, better brush up your skills and make sure your tools are in good order!  

Official site: http://www.flare-on.com/

 

 

Edited August 15, 2018 by kao

[GautamGreat]

FlareOn5 Challenge started and I'm already stuck on challenge #3

I managed to get all the 48 PNGs from but now I have no clue how to get the flag. Can someone give some hints

[Extreme Coders]

@GautamGreat The numbers in the images have a purpose.

[GautamGreat]

@Extreme Coders   

48 Files with 48 uniques number that means flag has 48 characters ?

[GautamGreat]

Nevermind I managed to solve it. 

Thanks

[GautamGreat]

On #4 we need to reverse that vuln JavaScript right?

[Rurik]

That JavaScript integrates with something else, so you'll likely have to attack it in its final form.

Or so I guess. It's where I'm at, and it's very frustrating :D I've not seen JS like that before, and hard to debug.

Also, anyone else have their Firefox debugger unable to set breakpoints? It just doesn't let me :((

[GautamGreat]

14 hours ago, Rurik said:

That JavaScript integrates with something else, so you'll likely have to attack it in its final form.

Or so I guess. It's where I'm at, and it's very frustrating I've not seen JS like that before, and hard to debug.

Also, anyone else have their Firefox debugger unable to set breakpoints? It just doesn't let me :((

I manged to break the JS file. It is first time, took so much time but yeah finally I did it  

[kao]

It's official - I finished as #4 this year!

 

 

 

Subjectively - first challenges are a bit harder than last year, probably due to the exotic targets (wasm, webinjects, etc..).

All in all, I enjoyed it immensely!

 

[Rurik]

Congrats @kao! I just saw the tweet.

Cue the hundreds of randos asking you for answers 😃

So far I've loved the challenges. Good variety, learned lots of new things. #6 went off rails a bit with a seemingly 'yet another reimplement this routine'. I'm hoping they pick up good after

Edited September 4, 2018 by Rurik

[kao]

@Rurik: Thanks!  I don't actually use Twitter, so random DMs will not bother me at all...

[Ahmad_k]

i know it is too late to solve these challenge but i did start today, i have some free time. For challenge 3 i also got all those 48 PNGs in automated way. Now i'm stuck, i have tried multiple flags with no success. i can't find the clue  

[kao]

Try to run those EXE files (with a correct password).

[Ahmad_k]

i did and i got all those 48 pngs. Each png has a number from 1 to 48, here i am stuck. The last pic show FLARE with two lego man on it.

[Rurik]

Each EXE produces *two* things. The PNG is just one of them.

[Ahmad_k]

yes i got it, thank you anyway  i forgot those little single char  

[Eskalina]

Hi. Anybody can help me with 12 challenge. I am extract 2 vm and recover key check function. But when i try find correct bytes, i can't do it. WTF?

[kao]

@Eskalina - IF you have recovered key check function correctly, you've done 95% of the task. After that it takes a few minutes of calculations to get the correct bytes.  So, most likely you have made a mistake somewhere..

 

Spoiler

If nothing else helps, read solutions of last year's FLARE - might give you some ideas on how to approach it.

 

[msr]

For #7 - I think I got "the trick", however I am a bit lost. Debugging inside some network functions and connect()s don't seem to connect (I have a listener and packet capture going) and then recv() randomly receives (same) bytes every time and just outputs those + @flare-on.com . Any tips on what I am missing ?

[kao]

@msr : 

Spoiler

Not all connect()s are the same.

 

Edited September 8, 2018 by kao

[bandit]

Stuck on ch#7 as well. None of my connect()s work either :(

[Sina_DiR]

@kao I'm totally stuck on level 10 without any idea what should I do, any suggestion?

[kao]

@Sina_DiR: Where exactly are you stuck? Driver does something, usermode EXE does something. Analyze what exactly they do.

1) To load and run the driver, you need a reasonably new CPU and VM. My configuration was Intel i5-2500K and VMWare 12 with "Virtualize Intel VT-x/EPT or AMD-V/RVI" option enabled. 
2) If you can't run driver for some reason (twitter commenters say they had some issues), just analyze it statically. Driver is based on open-source code, it should get you started.

[Sina_DiR]

@kao Thank you for your reply, I'm able to load the driver, I was trying to debug its driver but it seems nothing called from fhv.sys I have no idea about VMCALL so let me try again...

[bandit]

Any hints for ch#11? Trying to figure out the network comm between the sample and JJ-pc...

Any hints on decrypting the responses received from the pipe?