A case study in Penetration Testing
We haven’t been blogging as much as usual largely because we’ve been busy hacking things. So, we figured that we’d make it up to our readers by posting an article about one of our recent engagements. This is a story about how we covertly breached a highly sensitive network during the delivery of a Platinum level Penetration Test.
First, we should make clear that while this story is technically accurate certain aspects have been altered to protect our customer’s identity and security. In this case we can’t even tell you if this was for a private or public sector customer. At no point will ever write an article that would put any of our customers at risk. For the sake of intrigue lets call this customer Group X.
The engagement was designed to produce a level of threat that would exceeded that which Group X was likely to face in reality. In this case Group X was worried about specific foreign countries breaching their networks. Their concern was not based on any particular threat but instead based on trends and what we agreed was reasonable threat intelligence. They were concerned with issues such as watering holes, spear phishing, 0-day malware, etc. They had reason for concern given that their data was and still is critically sensitive.
We began work like any experienced hacker would, by performing social reconnaissance. Social reconnaissance should always be used before technical reconnaissance because it’s passive by design. Social reconnaissance when done right will provide solid intelligence that can be used to help facilitate a breach. In many cases social reconnaissance can eliminate the need for active technical reconnaissance.
Just for the sake of explanation, technical reconnaissance includes active tasks like port scanning, web server scanning, DNS enumeration, etc. Technical reconnaissance is easier to detect because of its active methods. Social reconnaissance, when done right, is almost impossible to detect because it is almost entirely passive. It leverages tools like Google, Maltego, Censys, etc. to gather actionable intelligence about a target prior to attack.
Our social reconnaissance efforts identified Group X’s entire network range, a misconfigured public facing document repository (that did not belong to Group X but was used by them and their partners/vendors), and a series of news articles that were ironically focused on how secure Group X was. One of the articles went so far as to call Group X the “poster child of good security”.
We began by exploring the contents of the aforementioned document repository. The repository appeared to be a central dumping ground for materials Group X wanted to share with third parties, including vendors. While digging through the information all of it appeared to be non-sensitive and mostly intended for public consumption. As we dug further we uncovered a folder called WebServerSupport and contained within that folder was a file called “encyrypted.zip”. Needless to say we downloaded the file.
We were able to use a dictionary attack to guess the password for the zip file and extract its contents. The extracted files included a series of web server administration guides complete with usernames, passwords, and URL’s. One of the username, password and URL combinations was for Group X’s main website (https://www.xyxyxyxyxy.com/wp-admin,username,password). When we browsed to https://www.xyxyxyxyxy.com/wp-admin we were able to login using the credentials. With this level of access we knew that it was time to poison the watering hole. (https://en.wikipedia.org/wiki/Watering_Hole)
To accomplish this we deployed our malware framework into the webserver (www.xyxyxyxyxy.com). Our framework is specifically designed to allow us to control who is infected. We are able to select targets based on their source IP address and other information identifying information. When a desired target connects to the watering hole (infected website) our framework deploys our 0-day pseudo-malware (RADON) into the victim’s computer system. RADON then establishes persistence and connects back to our command and control server. From there we are able take complete control of the newly infected computer.
Netragard RADON v2.0 Strand Generator
RADON is not the same RADON used by the National Security Agency (NSA) as was speculated by the InfoSec institute. RADON does appear similar in some respects. It relies on side channel communications that cannot be disrupted without breaking core network protocols. It was designed to be far safer than other tools that tend to leave files behind (like Metasploit’s meterpreter). All strands of RADON are built with an expiration date that when reached trigger a clean uninstall and render the original source inert. We designed RADON specifically because we needed a save, clean and reliable method to test our customers at high levels of threat.
After the malware framework was deployed and tested, we scheduled it to activate the next business day. The framework was designed to infect one target then sleep until we instructed it to infect the next. This controlled infection methodology helps to maintain stealth. By 9:30 AM EST our first RADON strand called home. When we reviewed the connection we learned that we had successfully infected a desktop belonging Group X’s CIO’s assistant. We confirmed control and were ready to begin taking the domain (which as it turns out was ridiculously easy).
One of the first things we do after infecting a host is to explore network shares. During this test we quickly located the “scripts” share, which contained all of the login scripts for domain users. What we didn’t expect was that we’d be able to read, write, and otherwise modify every single one of those startup scripts. We were also able to create new scripts, new files and directories within the scripts directory. So uploaded RADON to the share and added a line to every login script that would run RADON every time a user logged into a computer. We quickly infected everything on the network.
After parsing through the onslaught of new inbound RADON connections we were able to identify personal user accounts belonging to network administrators. As it turned out most of the administrators personal accounts also had domain admin privileges. We leveraged those accounts to download the username and password database (ntds.dit) from the domain controller. Then we used RADON to exfiltrate the password database and dump it on one of our GPU password-cracking machines. We were able to crack all of the current and historical passwords in less than 2 hours time. What really surprised us was that 90% of the passwords were exactly identical.
Initially we thought that this was due to an error. But after further investigation we realized that this common password could be used to login using all of the different domain accounts. It became even more interesting when we began to explore the last password change dates. We found that nearly 100% of the passwords had never been changed and that some of the accounts were over a decade old, still active, but no longer being used by anyone. We later found out that employees that had been terminated never had their accounts deactivated. When we confronted the customer with this they told us that it was their policy to not change passwords. When we asked them why they pointed to an article written by Bruce Schneier. (Sorry Bruce, but this isn’t the first time you’ve made us question you.)
At this point in the engagement we had more control over our customer’s infrastructure than they did. We were able to control all of their critical devices including but not limited to antivirus solutions, firewalls, intrusion detection and prevention systems, log correlation systems, switches, routers and of-course their domain. We accomplished this without triggering a single event and without any suspicion.
The last two tasks that remained were trophy gathering and vulnerability scanning. Trophy gathering was easy given the level of access that we had. We simply searched the network for .pdf, .doc,.docx,.xlsx, etc. and harvested files that looked interesting. We did find about a dozen reports from other penetration testing vendors as well. When we looked at those reports they presented Group X’s network as well managed and well protected. The only vulnerabilities that were identified were low and medium level vulnerabilities, none of which were exploitable.
When we completed our final task which was vulnerability scanning and vetting, our scanners produced results that were nearly identical to the other penetration testing vendor reports that we exfiltrated. Things like deprecated SSL, open ports, etc. were reported but nothing that could realistically lead to a network compromise. When we scanned Group X’s network from the perspective of an Internet based threat no vulnerabilities were reported. Our scans resulted in their security team becoming excited and proud because they “caught” and “prevented our intrusion attempt. When we told them to check their domain for a Netragard domain admin account, their excitement was over.