Hacking

Microsoft Zero-Day with No Patch!

Overview
CVE-2022-30190, known as Follina, was released by Microsoft on Monday, May 30th, 2022. The vulnerability resides within the Microsoft Support Diagnostics Tool (MSDT), which may allow an attacker to run arbitrary code with the privileges of the calling application. Microsoft Office applications use MSDT to troubleshoot and collect diagnostic information when something goes wrong.

This vulnerability was discovered by the independent cybersecurity researchers at nao_sec after they noticed a strange word document posted to VirusTotal. Using the Remote Template feature in Microsoft Word, an HTML file was pulled from a remote web server. It then made use of the “ms-msdt://” URI scheme to run a malicious payload. Experts are now saying this vulnerability is being exploited by attackers in the wild. Some security researchers have demonstrated execution of the malicious code merely by previewing the document in Windows File Explorer or Outlook.

Exploit
The video below demonstrates how easily this vulnerability can be exploited. Exploit code is now publicly available, making this process trivial. We will outline the steps taken in this video below:

An attacker downloads exploit code from GitHub.
This exploit code is then utilized to create the malicious Word document and stand up a web server to serve up the HTML file. In the video below, this Word document is called “sploit.docx.”
Once the user opens the Word document, you see the MSDT tool also fire off. MSDT is also commonly referred to as “Program Compatibility Troubleshooter.”
The producer of this video then shows you that both a cmd.exe process and powershell.exe process have been launched on the system. At this point, the document can be closed, but the malicious process is still running.
The demo then shows a Cobalt Strike window. Cobalt Strike is a command-and-control framework used for maintaining persistent access on compromised systems. You can see in the video that a “beacon” has been launched on the system. A beacon is an agent on the system that allows an attacker to maintain persistent access and run arbitrary code.
At this point the producer of this video runs “whoami” on the system itself to show you which user account launched the Word document. They then flip back to Cobalt Strike and run “whoami” from the interactive beacon. This displays the same user account. Persistent remote code execution achieved.

What To Do?
At this point in time, Microsoft has not released an official fix for this vulnerability. They are recommending that the MSDT URL protocol be disabled in order to protect systems from this vulnerability. That guidance can be found here. nGuard offers a bevy of services that can help prevent and identify these types of attacks. Both Social Engineering simulations and Social Engineering Awareness Training can assist your organizations employees in identifying these types of attacks. Internal Penetration Testing can boost the overall security posture of your internal network. If a machine on your network does become compromised, you have assurance that the adversary won’t make it very far. Lastly, Managed Event Collection & Correlation gives you 24×7 monitoring from advanced log analysis tools and nGuard professionals who are trained to detect suspicious activity.

FBI Secretly Removing Malware

Late last week, Attorney General Merrick Garland announced that the FBI was removing malware from computer systems around the world in an attempt to thwart Russian cyber-attacks. In March, the White House warned that Russia could be targeting critical infrastructure in the United States. The malware that is being removed from systems by the FBI is reported to allow an arm of the Russian military called the GRU to take over machines and create botnets for DDoS attacks. The GRU is Russia’s largest foreign intelligence agency responsible for handling multiple forms of military intelligence.

The Justice Department says that this strain of malware is designed to compromise externally facing firewalls and loop them into a botnet called Cyclops Blink. The botnet is controlled by a notorious group called Sandworm that has been known to work with the GRU. The DOJ warned owners of infected devices that their machines were part of this Cyclops Blink botnet, but decided that it was not worth the wait and took it upon themselves to remove the malware from infected devices.

Through secret court orders, the Justice Department and FBI were able to quietly remove this malware from infected devices across the globe. After removing the malware, the FBI also closed the management port that was being used as the attack vector. The Biden administration has been ramping up their cyber security operations since the breakout of war in Ukraine. While Ukraine has been the number 1 target of cyber attacks over the last couple months, authorities warn that critical infrastructure organizations in the United States could be next.

Performing external penetration testing and having a formal external vulnerability management program can help to thwart attacks like this. By identifying these vulnerabilities and patching them before adversaries get their hands on them, you can protect your externally facing machines from becoming a part of a worldwide botnet.

Lapsus$ Crime Gang: Hacking Microsoft, Okta, and More

Lapsus$ is a hacking group that first appeared in December of 2021 when they were extorting Brazil’s Ministry of Health. Recently they have been in the news for posting information and screenshots from internal breaches of companies like Microsoft, Nvidia, and Okta. Lapsus$ is unorthodox in their operations in that they do not operate on the dark web or on any social media platforms. Instead, Lapsus$ leverages email and a public Telegram channel which now has over 45,000 members. Lapsus$ does not attempt to hide any of their activity or cover their tracks. In fact, they have been known to join Zoom calls of organizations they have compromised and interrupt their incident response process.

With such high profile targets, it was initially thought that Lapsus$ was state-sponsored but it has been reported that their head is a multi-millionaire 16-year-old teenager in Oxford, England. Researchers tracking the group have said, “The teen is so skilled at hacking — and so fast — that researchers thought the activity they were observing was automated.” Lapsus$ has been spotted recruiting on various online platforms since November 2021. Recruiting ads offering $20,000 a week to perform SIM swapping for AT&T, Verizon, and T-Mobile customers.

Although the group has done significant damage already, the good news is London Police have arrested seven individuals, all 16 to 21 years old in connection with the hacking group.

Microsoft Breach Last week, Microsoft confirmed Lapsus$ was responsible for obtaining and leaking about 37 GB of pieces of their source code for Bing, Cortana, and over 250 Microsoft projects via access it had through a single account. Lapsus$ initially obtained access via stolen credentials which allowed privileged access and the exfiltration of data.

Microsoft has been tracking Lapsus$ for some time now, calling it DEV-0537. Microsoft’s Threat Intelligence Center stated, “… the objective of DEV-0537 actors is to gain elevated access through stolen credentials that enable data theft and destructive attacks against a targeted organization, often resulting in extortion. Tactics and objectives indicate this is a cybercriminal actor motivated by theft and destruction.”

Okta Breach

Okta, a single-sign-on identity management service that works in cloud and on-premises environments announced Lapsus$ was able to gain access to one of their employee’s laptops for five days in January. The access was originally obtained through subprocessor Sykes Enterprises which is owned by Sitel Group. Lapsus$ utilized compromised credentials to access Sykes Enterprises. It was discovered the credentials were used on VPN gateways. Once Lapsus$ had access they discovered a file on Sitel’s network called DomAdmins-LastPass-xlsx. This would indicate a file with Domain Administrator passwords from the password manager LastPass was exported and saved locally. Lapsus$ was able to pivot to Okta’s network and posted screenshots of their access.

Some screenshots from the incident response investigation were posted showing the timeline of events and activity. Activity such as searching Bing for privilege escalation tools on GitHub, disabling endpoint protection agents, and searching and downloading Mimikatz –a tool to extract and save authentication credentials and Kerberos tickets from a host — were performed during the attack.

Okta has faced a wave of criticism on their slow response to the breach after receiving the incident response report. Okta chief security officer David Bradbury said the company “should have moved more swiftly to understand its implications.” As of now, Okta has stated the breach has impacted 366 of their customers during the 5-day period of the attack.

Other Attacks

Lapsus$ has been highly active in the recent months. To read more about other attacks they have carried out on high-profile organizations click the links below.

How nGuard Pwned Your Network Video Series | Part 3 of 3

In this 3-part series we are demonstrating how nGuard most commonly gains an initial foothold on internal networks, then takes that initial access and pivots through the network to obtain full command and control over systems. If you missed parts I or II, check them out here and here.

In this third part, we are going to round out our initial compromise, show you how we can obtain full command and control over a host, and show you the results of our password cracking attempts. For this part we are going to be using PowerShell Empire. The original tool was deprecated, but later was revived and now is maintained on GitHub. The framework has multiple modules and listed on the GitHub they say, “Empire 4 is a post-exploitation framework that includes pure-PowerShell Windows agents, Python 3.x Linux/OS X agents, and C# agents. It is the merger of the previous PowerShell Empire and Python EmPyre projects. The framework offers cryptologically-secure communications and flexible architecture. On the PowerShell side, Empire implements the ability to run PowerShell agents without needing powershell.exe, rapidly deployable post-exploitation modules ranging from key loggers to Mimikatz, and adaptable communications to evade network detection, all wrapped up in a usability-focused framework.”

To set this attack up and eventually have persistent command and control of a host, which will be called agents, we need to configure the server and the client. In separate terminals we will run these commands:

powershell-empire server
powershell-empire client

Once those are started, we can now set up a listener. In this attack we will need to configure the client to use an http listener. To do this we will configure the Bind IP and host to use our local IP and choose a port to run on.

After the listener is executed, we will see our sever reflect the results:

The next thing we will want to configure is our stager, which will output the encoded PowerShell command we want to execute on our compromised host. To do this we use the http listener and input the command generate.

Now that we have our encoded PowerShell, we want to go back to our Responder and ntlmrelayx tools. We will leave Responder running in the same configuration used in Part II and only have to change our ntlmrelayx command. This time we will add the -c option to have the PowerShell command run on the host, rather than dumping the SAM hashes.

Once our connection using the ntlmrelayx tool is created and our PowerShell command executes we will receive a connection back to our local machine from a compromised host in the form of an agent.

Now that we have an agent, there are many modules and commands we can run to further exploit the compromised host. In the video demonstration below you will see examples of commands like whoami for basic information about the host and mimikatz to look for more hashed and cleartext credentials on the host.

In part I we talked about loading the hashes in our password cracker and when reviewing we can see the password hash for two users were cracked in 4 minutes and 26 seconds!

Although we were able to crack the password in a relatively short time, environments with complex password requirements may take a significant amount of time to crack or will not during the time you have on an engagement. Since this task may be time consuming or unsuccessful it is much easier and quicker to utilize the hashes and not have to rely on discovering cleartext credentials.

Check out the video below to see all these steps live in action:

IIf you have any questions about this attack or want to see if nGuard can perform attacks like this on your internal network during one of our internal penetration testing assessments please reach out to an Account Executive.

How nGuard Pwned Your Network Video Series | Part 2 of 3

In this second part, we are going to take the hashes we have intercepted from part I and build upon it. We are going to relay the hashes to other hosts on the network and see what permissions and access we have. This attack is different than another common attack called pass-the-hash (PTH). Since the hashes we have captured with our Responder tool are Net-NTLM hashes, we cannot perform the PTH attack. Instead, we relay them to discover local NTLM hashes, which we can perform the PTH attack with.

In this attack we are going to use CrackMapExec and Impacket’s ntlmrelayx Python module. CrackMapExec is a post-exploitation tool that is used in assessing Active Directory environments. This is a tool with many features, but we will only be showing the feature of generating a list with hosts that have Server Message Block (SMB) Singing disabled/not required. To do this we run the command:

crackmapexec smb <IP Range to scan> –gen-relay-list <outputFileName.txt>

This command specifies the name of the tool, the protocol we want to scan for (SMB), command to generate a list, and the name of the file where we want to output the hosts with SMB signing disabled. In the screenshot below you can see we discover two hosts with SMB singing as false (disabled).

The Impacket module ntlmrelayx.py allows us to take the Net-NTLM hashes we captured in Responder and perform SMB relay attacks on the hosts discovered with SMB signing disabled utilizing CrackMapExec. The default behavior of this module is to dump the local Security Account Manager (SAM) file which contains local NTLM hashes. These are hashes we can now perform the PTH with. The two screenshots below demonstrate how this attack is carried out.

As we obtain these hashes throughout these attacks, we will always upload them into our password cracking machine and attempt to discover the cleartext password. As demonstrated in these videos so far, there are many things we can do with hashes, but working with the cleartext is always easier.

Here is a video demonstrating this in action:

In part 3 we will take the access we have gained, use that to setup full command and control over a specific host, and view the results of the hashes being uploaded into our password cracker. If you have any questions about this attack or want to see if nGuard can perform attacks like this on your internal network during one of our internal penetration testing assessments please reach out to an Account Executive.

How nGuard Pwned Your Network Video Series | Part 1 of 3

This is a 3-part series on how nGuard most commonly gains an initial foothold on your internal network, then takes that initial access and pivots through the network to obtain full command and control over systems. These are attacks that are present in over 90% of the networks we conduct internal penetration testing on. This will show you how quickly nGuard or an attacker can take an initial foothold and create persistent access. Some of the systems shown throughout this series will be Windows 7 machines but make no mistake, these are attacks that work in modern day Windows 10 environments.The first video will utilize a tool called Responder. This is a LLMNR (Link-Local Multicast Name Resolution), NBT-NS (NetBIOS Name Service) and MDNS (multicast DNS) poisoner. It will answer to specific NBT-NS queries based on their name suffix. By default, the tool will only answer to File Server Service request, which is for SMB. By responding to these broadcasts, nGuard can impersonate the host being requested and intercept future requests that may contain sensitive information. Through these requests, an attacker will receive the user’s hashed credentials, which can then be taken offline for cracking or used in other attacks.

The image below shows exactly how this works:

Here is the output to the terminal with a user’s hashed credentials:

The video below shows how this first step unfolds:

Stay tuned for part 2 where we will take these hashed credentials and relay them to other machines/systems which will discover other hosts we can gain access to on the network. If you have any questions about this attack or want to see if nGuard can perform attacks like this on your internal network during one of our internal penetration testing assessments please reach out to an Account Executive.