Last time we touched base, we described our journey into starting our work at the LCDI and our growth as interns, as well as some of the things we learned so far. Today, however, we wanted to touch on a different subject. Many forget that the mistakes, accidents, hiccups, and small failures of any project are just as important as the successes. Sometimes they’re more important as their lessons are greater than those you learn miraculously getting something right the first try. Although we’d like you to think we’re hyper-intelligent computer networking wizards who are ahead of the game, we aren’t. We have made some blunders, a decent number of errors, and a handful of happy accidents on this quest—but we are all the better for it.

The first scans we ran were on a small network of Raspberry Pis which were all running different services. One of these services was a Windows machine, and the unexpected hassle of setting up such a device was grueling. The only Windows OS “optimized” to work on a Pi is Windows IoT Core, which is Microsoft’s crack at a lightweight Internet of Things (IoT) operating system. If you’ve never heard of it, it’s probably because Microsoft would rather not advertise it. The service is free to download, but is not, in fact, designed optimally.

After first burning Windows IoT to a microSD, we plugged the SD into the Pi and turned it on. Windows IoT failed to boot, not once, not twice, but so many times we lost count. Even after we followed instructions step-by-step from both Microsoft and other websites, it refused to cooperate. After about two hours of attempting to boot Windows IoT, reburning it to the SD, trying a different SD, and failing some more, Windows IoT booted successfully without us doing anything differently the next day.

Once we logged onto Windows IoT, we needed to set it up to work with SSH so that we could input commands to it from our workstations. We didn’t need Windows IoT for anything specific, we just needed some sort of Windows machine to secure a connection to. However, getting Windows IoT to establish SSH connections required another three hours of trial, error, and scratching heads. Finally, we turned the machine off, reburned the SD with another fresh copy of Windows IoT, turned it on, and lo and behold, it worked—again without us doing anything differently. This worked for about a week until one day, the password and SSH key randomly changed during a scan cycle.

The palpable frustration we experienced as a team cannot be understated. But the moral of the story is keep working at it. We didn’t necessarily have to use Windows IoT. In fact, we would have preferred we didn’t, after the problems it caused. But we got it to work, and that’s what really counts.

Vulscan is a plugin for Nmap that adds vulnerability database checking functionality. It’s designed to take advantage of Nmap (which, if you remember from last time, is the software we’re using to scan the network) and its more invasive functions to diagnose potential problems that may occur with the machine automatically. This service was the thing we were looking for; without it, a person would have to diagnose all vulnerabilities by looking at our reports, which are sometimes very long, and may not provide all the necessary information.

We set up Vulscan early, but ran into problems as it didn’t run due to how we set up Nmap. Once we figured out our mistake and got Vulscan working, it became clear that the script was not optimized. Because it uses Nmap’s scripts for parsing potential vulnerabilities, the best Vulscan can do is guess what vulnerabilities are present. And it will give you every single guess it has, even the ones it knows aren’t likely to be true.

This headache was compounded when we learned that Vulscan would not run in our own script. It turned out we were actually using a slightly different version of Nmap, called libNmap. This version of Nmap is designed to run in a Python script which meant Vulscan didn’t recognize it as Nmap. So, our choice was to either scrap the completed script we made, which worked as intended, putting us at least a week or two behind, or abandon Vulscan and stick with what we had.

Ultimately, we decided to ditch Vulscan rather than sacrifice the valuable time spent on our script. Although it contradicts the last anecdote, sometimes it’s better to cut your losses and stick with what works rather than fix what’s broken.

Now, I know that these stories may leave the reader on a sour note, and that was somewhat intentional. Our team experienced these major frustrations and it helps to understand them for the reasons I described above. I hope that if people in the future ever try to replicate this project, they heed the advice presented here.

To learn more about this and other blogs of the LCDI visit us here: LCDI Blog.

Stay in the loop on our current and upcoming projects and events by following us on Facebook,  Twitter, or Instagram. 

The post Windows IoT, Vulscan, and Other Problematic Programs appeared first on The Leahy Center for Digital Investigation.