The security research community is full of grey beards that earned their stripes writing exploits against mail servers, domain controllers, and TCP/IP stacks. These researchers started writing exploits on platforms like Solaris, IRIX, and BSDi before moving on to Windows exploitation. Now they run companies, write policy, rant on twitter, and testify in front of congress. I’m not one of those people; my education in security started after Windows Vista and then expanded through Capture the Flag competitions when real-world research got harder. Security researchers entering the industry post-2010¹ learn almost exclusively via Capture the Flags competitions.

Occasionally, I’ll try to talk a grey beard into playing capture the flag. It’s like trying to explain Pokemon to adults. Normally such endeavors are an exercise in futility; however, on a rare occasion they’ll also get excited and agree to try it out! They then get frustrated and stuck on the same problems I do – it’s fantastic for my ego².

“Ugh, it’s 90s shellcoding problems applied today.”
— muttered during DEFCON 22 CTF Quals

Following a particularly frustrating CTF we were discussing challenges and how there are very few Windows challenges despite Windows being such an important part of our industry. Only the Russian CTFs release Windows challenges; none of the large American CTFs do.

Much like Cold War-era politics, the Russian (CTFs) have edged out a Windows superiority, a Windows gap.

Projected magnitude of the Windows gap

The Windows gap exists outside of CTF as well. Over the past few years the best Windows security research has come out of Russia³ and China. So, why are the Russians and Chinese so good at Windows? Well, because they actually use Windows…and for some reason western security researchers don’t.

Let’s close this Windows gap. Windows knowledge is important for our industry.

Helping the CTF community

If Capture the Flag competitions are how today’s greenhorns cut their teeth, we should have more Windows-based challenges and competitions. To facilitate this, Trail of Bits is releasing AppJailLauncher, a framework for making exploitable Windows challenges!

This man knows Windows and thinks you should too.

As a contest organizer, securing your infrastructure is the biggest priority and securing Windows services has always been a bit tricky until Windows 8 and the introduction of AppContainers. AppJailLauncher uses AppContainers to keep everything nice and secure from griefers. The repository includes everything you need to isolate a Windows TCP service from the rest of the operating system.

Additionally, we’re releasing the source code to greenhornd, a 2014 CSAW challenge I wrote to introduce people to Windows exploitation and the best debugger yet developed: WinDbg. The repository includes the binary as released, deployment directions, and a proof-of-vulnerability script.

We’re hoping to help drag the CTF community kicking and screaming into Windows expertise.

Windows Reactions

Releasing a Windows challenge last year at CSAW was very entertaining. There was plenty of complaining⁴:

<dwn> how is this windows challenge only 200 points omg
<dwn> making the vuln obvious doesn’t make windows exploitation any easier ;_;

<mserrano> RyanWithZombies: dude but its fuckin windows
<mserrano> even I don’t use windows anymore
<@RyanWithZombies> i warned you guys for months
<mserrano> also man windows too hard

<geohot> omg windows
<geohot> is so hard
<geohot> will do tomorrow
<geohot> i don’t have windows vm

<ebeip90> zomg a windows challenge
<ebeip90> <3
[ hours later ]
<ebeip90> remember that part a long time ago when I said “Oh yay, a Windows challenge”?

<ricky> Windows is hard
<miton> ^

Some praise:

<cai_> i liked your windows one btw :)

<MMavipc> RyanWithZombies pls more windows pwning/rce

<CTFBroforce> I was so confused I have never done a windows exploit
<CTFBroforce> this challenge is going to make me look into windows exploits
<CTFBroforce> I dont know how to write windows shell code

<spq> thx for the help and the force to exploit windows with shellcode for the first time :)

It even caused some arguments among competitors:

<clockish> dudes, shut up, windows is hard
<MMavipc> windows is easy
<MMavipc> linux is hard

We hope AppJailLauncher will be used to elicit more passionate responses over the next few years!

Footnotes

1. Many of the most popular CTFs started in 2010 and 2011: Ghost in the Shellcode (2010), RuCTFe (2010), PlaidCTF (2011), Codegate (2011), PHDays (2011). Very few predate 2010.
2. Much like watching geohot fail at format string exploitation during a LiveCTF broadcast: https://www.youtube.com/watch?v=td1KEUhlSuk
3. Try searching for obscure Windows kernel symbols, you’ll end up on a Russian forum.
4. The names have not been changed to shame the enablers.