On Windows 7 and Windows 2008 server, the Windows NTLM Vulnerability allows a remote attacker to hijack the user’s session, and perform actions on their behalf on the network. The attacker can get the targeted user’s NTLM credentials by exploiting any software with a vulnerability that is using NTLM authentication. Once the attacker has the user’s NTLM credentials, they can then use those to hijack their session, and take over the user’s Windows session. This means that the attacker can view, change, or delete any information on the user’s Windows machine, and even take over the user’s account if they have one on the machine. As mentioned above, this problem can be easily exploited by an attacker who is on the same network as the user. The attacker can send a specially crafted message that contains a link to a website. The link will be displayed on the user’s screen, and they click on it to continue. The attacker can then exploit this to get the user’s NTLM credentials, and use those to take over their session. When this happens, the attacker can view anything on the user’s Windows machine, and even take over the user’s account if they have one on the machine. This can be done by making a new user account on the Windows machine, and then using that account to take takeover of the original account.
Microsoft Windows NTLM Vulnerability - Example
A website owner was attacked by an individual who had exploited the NTLM vulnerability. The attacker got into their account and had full access to all of the website’s data.
Microsoft NTLM Vulnerability - Code Walkthrough
The NTLM vulnerability is a vulnerability in Windows 7 and Windows 2008 server that allows for an attacker to hijack another user’s session and take over their account. This attack exploits any software with a vulnerability that is using NTLM authentication, which can be done by sending a specially crafted message to the victim. The exploit doesn’t require any special tools or skills to carry out, just some patience and time.
First, we need to find out the target machine’s IP address. We can do this by looking at the victim’s computer name in the output below:
Once we know the target computer’s IP address, we need to find out its associated NetBIOS name. This can be found on the computer itself by typing netbiosname -n (network-bios-name) into the command prompt or PowerShell window.
Next, we need to send our victim an email with a malicious link in it that will cause them to click on it without realizing what it is. To generate this malicious link, you can use Microsoft's Invoke-WebRequest tool along with an anonymous proxy address. You'll have to change the destination of your request from http://www.example.com/index.html?y=2%20&x=1%20&z=3%20to %21://zlm2k7k8zjd5h6lblm5pw4
How to Detect if You are Vulnerable?
To find out if you are vulnerable, run the following command:
Set-ItemProperty -Path "HKLM:\System\CurrentControlSet\Control\LSA" -name NtlmSignatureLevel -Value 3
If your machine is vulnerable, this will display the following error message:
The security setting for the LSA authentication level in registry key HKLM:\System\CurrentControlSet\Control\LSA has been modified. This may cause LSASS to stop working and could allow a remote attacker to take complete control over this system. Are you sure you want to continue?
This means that your machine is vulnerable.
Microsoft Windows NTLM Authentication Bypass
Microsoft Windows NTLM Authentication Bypass is a vulnerability which can be exploited by an attacker on the same network as the targeted user. The vulnerability allows the attacker to bypass authentication, and log on to the targeted machine with the user’s credentials. This means that if you have a Windows machine, and you’re using NTLM authentication for your configuration settings, then it is highly likely that you are vulnerable to this attack. As mentioned above, this vulnerability can be exploited by an attacker who is on the same network as the user. The attacker can send a specially crafted message that contains a link to a website. The link will be displayed on the user’s screen, and they click on it to continue. The attacker can then exploit this to get the user’s NTLM credentials, and use those to take over their session. When this happens, the attacker can view anything on the user’s Windows machine, and even take over their account if they have one on the machine.
How to Check if Windows is Vulnerable?
To check if Windows is vulnerable to this type of attack, a user should first open a command prompt. Type in the following command:
C:\>netsh nla show credentials
This will show the current local network credential cache, including any NTLM credentials that are stored on the system. If an NTLM-based credential is found on this list, then Windows is definitely vulnerable to this type of attack.
Timeline
Published on: 10/11/2022 19:15:00 UTC
Last modified on: 10/12/2022 14:46:00 UTC