Category: Attacking domain trusts

Attacking domain trusts

31.10.2020 By Meztishakar

In this article, we will discuss the causes of Trust relationship failed error and some solutions on how to restore secure channel between the workstation and the Active Directory domain. In what case we can get this error? For example, when a user is trying to login to workstation or server with domain account credentials and after entering the username and its password a window appears with an error message :. The security database on the server does not have a computer account for this workstation trust relationship.

When you join the computer to Active Directory domain, the new computer account is created for your device and a password is set for it like for AD users. Trust relationship at this level is provided by the fact that the domain join is performed by a Domain administrator or another user with delegated administrative permissions. Each time when domain computer login to the AD domain, it establishes a secure channel with the nearest domain controller and sends the computer credentials.

In that case, trust is established between the workstation and domain and further interaction occurs according to administrator-defined security policies. The computer account password is valid for 30 days by default and then automatically changes. You must keep in mind that the password is changed by the computer according with the configured domain Group Policy. This is similar to the changing user password process. You can specify the number of days between 0 and by default it is 30 days.

You can configure the machine account password policy for a single computer through the registry. To do this, run regedit. Edit the parameter MaximumPasswordAge and set the maximum validity time of the computer password in the domain in days. The Active Directory domain stores the current computer password, as well as the previous one. If the password was changed twice, the computer that is using an old password will not be able to authenticate on the domain controller and establish a secure connection channel.

Your computer can use the NETLOGON service to change the password automatically during the next domain logon if its password is older than 30 days note that the local computer password is not controlled by AD, but by the computer itself. Run the command with the computer name:. Therefore, even if you did not power on your computer for a few months, the trust relationship between computer and domain still be remaining and the computer password will be changed at first registration of your workstation in the domain.

Trust relationship may fail if the computer tries to authenticate on a domain with an invalid password. Typically, this occurs after reinstalling Windows, then the system state was restored from an image backupVirtual machine snapshot, or when performing computer cloning without running sysprep.

In this case, the current value of the password on the local computer and the password stored for a computer object in the AD domain will be different. You can verify that the computer local password is in sync with computer account password on the domain controlled with the Test-ComputerSecureChannel cmdlet.

You can use a simple form:. First of all, open the Active Directory Users and Computers ADUC snap-in and make sure that the problem computer account is present in the domain and is not disabled. The most obvious old-school way to restore the trust relationship of your computer in the domain is:.For their talk, this use case was presented in the context of one forest with multiple sub-domains; however, recently Will was able to apply the same recipe to compromise DCs on separate foreign forests with a two-way trust set up.

He also covers specific configurations that you can apply in your environment to potentially help mitigate the attack. Therefore, we cannot assume that an adversary will always use the RPC printer server to execute this attack. In addition, it is important to understand that attacks like this one do not happen in a vacuum.

There are other events and actions that might need to happen before, during and after to accomplish the main objective of the operation.

Will provided a lot of information on how the attack works from an offensive perspective in his post. As a defender, it is very important to understand every step taken by the adversary to identify potential data sources that could provide enough information to help on the detection of the attack activity. Before we start simulating and documenting the detection of this attack, it is very important to understand what the attacker does and why. In this section, I will provide several of the articles and documentation that helped me understand the attack a little bit better.

Simply put, delegation allows a server application to impersonate a client when the server connects to other network resources. According to Microsoft DocumentationMicrosoft defines delegation as the action to give authority to a server and allow it to act on behalf of a client with other remote systems in an environment.

Servers talking to other servers to perform tasks on behalf of clients is common. The are three types of Kerberos delegations, and they can be summarized in the table below:.

According to Microsoft Docswhen a user requests access to a service backend server via a another service frontend server with unconstrained delegation the following happens:. The server, with unconstrained delegation configured, can ultimately use the forwarded TGT not only to access other non-requested services in the network, but to execute attacks such as DCSync if it is a Domain Controller TGT.

You can read more about the details provided above in here. As you know, the abuse of the unconstrained delegation concept is not new. However, what is very interesting and bad at the same time is that an attacker could also use this technique across foreign forests with a two-way-trust set up. Forest trusts ended up not being security boundaries after all. Microsoft Docs define trust as a relationship established between domains that enables users in one domain to be authenticated by a domain controller in the other domain.

When a new domain is added to the root domain, two-way transitive trusts are created by default. This is very important to understand since there might be Windows Security events that could show us activity between two forests during the attack.

According to Microsoft Docsit is based on the Remote Procedure Call RPC protocol that supports synchronous printing and spooling operations between a client and server, including print job control and print system management.

Therefore, I would expect to see network connections over port between the source and target servers. It can be used to create a remote change notification object that monitors changes to printer objects and sends change notifications to a print client. I hope this helped you to have some initial background before running the attack and document the potential data sources that could help us validate the detection of the new technique variation presented by Will.

Attacks between trusts between domains

Two forests with a two-way trust. Will provided an excellent layout of what the attack might look like in his post. I love this image because it adds some specific details for each step. From an elevated prompt cmd. You might need to run step 2 again if you do not get anything on your Rubeus Prompt from step 1.Domain trusts provide a mechanism for a domain to allow access to resources based on the authentication procedures of another domain.

Empire has modules for enumerating domain trusts. PoshC2 has modules for enumerating domain trusts. TrickBot can gather information about domain trusts by utilizing Nltest. Employ network segmentation for sensitive domains.

System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation but as part of a chain of behavior that could lead to other activities based on the information obtained. Remote access tools with built-in features may interact directly with the Windows API to gather information. The sub-techniques beta is now live! Read the release blog post for more info. Priority Definition Planning.

Assess current holdings, needs, and wants. Assess leadership areas of interest. Create implementation plan. Create strategic plan. Derive intelligence requirements. Generate analyst intelligence requirements. Identify analyst level gaps.

attacking domain trusts

Identify gap areas. Priority Definition Direction. Task requirements. Target Selection. Determine highest level tactical element. Determine operational element.

Determine secondary level tactical element. Determine strategic target. Technical Information Gathering. Conduct active scanning. Conduct passive scanning. Conduct social engineering. Determine 3rd party infrastructure services. Determine domain and IP address space. Determine external network trust dependencies. Determine firmware version. Enumerate client configurations. Enumerate externally facing software applications technologies, languages, and dependencies.

Identify security defensive capabilities.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Information Security Stack Exchange is a question and answer site for information security professionals. It only takes a minute to sign up. Domain administrators of any domain in the forest have the potential to take ownership and modify any information in the Configuration container of Active Directory.

These changes will be available and replicate to all domain controllers in the forest. But there is no specific description of how. In Security Considerations for TrustsMicrosoft list two more specific issues:. Are there any other attacks that are specific to domain trusts? SMB Replay attack isn't specific to trust. Also, how does the writing to Configuration OU can be achieved and what can you write from the other domain? If your domain is now in the search domain of the trusted domain you can use shortname replacements autodiscovery etc to try and trick client systems into accessing your resources insecurely and popping into social engineering environments.

This is generally a very bad idea if you're doing this with a third party. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Ask Question. Asked 7 years, 9 months ago. Active 7 years, 8 months ago. Viewed 6k times. Microsoft in their KB Articles Domain Trustsection "Considerations About Trusts" write that: Domain administrators of any domain in the forest have the potential to take ownership and modify any information in the Configuration container of Active Directory.

Konrads Konrads 5 5 silver badges 15 15 bronze badges. This is a very good question. It will probably get a lot more love on Security. I've flagged this question for moderator review to see if they agree. DMN1, open the active directory users and groups, and connect to DC1.

Then you expand the tree of the directory and modify the objects. The changes are saved and replicated. For example, try changing ownership of objects.

Fix Trust relationship failed issue without domain rejoining

AndrewSmith I don't think you can do that - domain admin privilege is non transitive unless explicitly added. Active Oldest Votes. You can enumerate users You can enumerate computers You can query DNS for interesting information If your domain is now in the search domain of the trusted domain you can use shortname replacements autodiscovery etc to try and trick client systems into accessing your resources insecurely and popping into social engineering environments.

Ori Ori 2, 1 1 gold badge 12 12 silver badges 29 29 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password.Active Directory Security. Jan 01 There are many ways an attacker can gain Domain Admin rights in Active Directory. This post is meant to describe some of the more popular ones in current use.

The unfortunate reality for most enterprises, is that it often does not take long from an attacker to go from domain user to domain admin. The attack frequently starts with a spear-phishing email to one or more users enabling the attacker to get their code running on a computer inside the target network. We start with the attacker having a foothold inside the enterprise, since this is often not difficult in modern networks.

Furthermore, it is also typically not difficult for the attacker to escalate from having user rights on the workstation to having local administrator rights. This escalation can occur by either exploiting an unpatched privilege escalation vulnerability on the system or more frequently, finding local admin passwords in SYSVOL, such as Group Policy Preferences. Most of the time, the following XML files will contain credentials: groups. Other file types may also have embedded passwords often in clear-text such as vbs and bat.

You would think that with a released patch preventing admins from placing credentials in Group Policy Preferences, this would no longer be an issue, though I still find credentials in SYSVOL when performing customer security assessments.

There are detection methods available to ensure that attempts to exploit MS are identified and flagged. Thanks to Gavin Millard gmillard on Twitterwe have a graphic that covers the issue quite nicely wish I had of thought of it!

Put simply, exploiting MS takes less than 5 minutes and enables an attacker to effectively re-write a valid Kerberos TGT authentication ticket to make them a Domain Admin and Enterprise Admin. Then while boarding the plane, you are escorted to the cockpit and asked if you would like coffee before taking off. End up with a ccache file. Kerberoast can be an effective method for extracting service account credentials from Active Directory as a regular user without sending any packets to the target system.

This attack is effective since people tend to create poor passwords. Furthermore, most service accounts are over-permissioned and are often members of Domain Admins providing full admin rights to Active Directory even when the service account only needs to modify an attribute on certain object types or admin rights on specific servers. This means that Kerberoast can attempt to open the Kerberos ticket by trying different NTLM hashes and when the ticket is successfully opened, the correct service account password is discovered.

Note: No elevated rights are required to get the service tickets and no traffic is sent to the target. The most effective mitigation of this attack is ensuring service account passwords are longer than 25 characters. Managed Service Accounts and Group Managed Service Accounts are a good method to ensure that service account passwords are long, complex, and change regularly.

A third party product that provides password vaulting is also a solid solution for managing service account passwords. Think of it as a dance. Compromise a single workstation, escalate privileges, and dump credentials.

Laterally move to other workstations using dumped credentials, escalate privileges, and dump more credentials. This usually quickly results in Domain Admin credentials since most Active Directory admins logon to their workstation with a user account and then use RunAs which places their admin credentials on the local workstation or RDP to connect to a server credentials can be grabbed using a keylogger.

Trust relationship between two domains

Step 1: Compromise a single workstation and exploit a privilege escalation vulnerability on the system to gain administrative rights. Run Mimikatz or similar to dump local credentials and recently logged on credentials. Step 2: Using the local Administrator credentials gathered from Step 1 attempt to authenticate to other workstations with admin rights.

This is usually successful since managing local Administrator account passwords have been difficult to do correctly now you should probably just use Microsoft LAPS. If you have the same administrator account name and password on many, or all, workstations, gaining knowledge of the account name and password on one, means admin rights on all.The main aim of this article is to show how much it is important to keep systems up to date with the latest Security patches; in particular, this post is about Security in corporate Windows environments.

Generally, in companies with a discrete number of Windows systems, it is common to set up a domain using a system called Active Directory. Basically it implements a number of processes and services which, among the other things, simplify the management of Windows user accounts inside a domain network so as to handle them in a centralized way. A server which runs Active Directory Domain Services takes the name of Domain Controller DC : through its configuration it is possible to define rules and policies which are applied to users and computers belonging to the domain.

An account with administrator privileges over the domain belongs to the Domain Admin group: it has administrator rights over all the machines registered to the domain, even on the DC. Once you have administrator privileges on the domain you can essentially do everything you want; this is why it is important to secure the domain in such a way that only a restricted group of authorized accounts that really needs them have those rights.

Another important aspect about the Domain Controller Security is that, while passwords for local users are stored inside the machine they have been defined in, passwords for domain users are stored on the DC itself. To simulate the attack to the domain, we can setup an Active Directory virtual laboratory environment with a Windows Server R2 acting as Domain Controller and a Windows 7 SP1 bit client in order to emulate an employer workstation registered to the domain.

The attacker will use the distro Kali Linux on which it is installed by default the notorious Metasploit Framework. After an initial Information Gathering during which he discovers Java 6u23 installation on client workstations, he starts the attack.

Through the info command we can take a look at the description that reports a lot of useful informations like the list of platforms affected, reliability Rank, vulnerability disclosure date, module authors, Common Vulnerability and Exposures CVE identifier and, of course, the options we need to set up to run the exploit:.

This kind of exploits starts a webserver and hosts the malicious code on a webpage, so, when the victim visits the url, it executes. Generally attackers trick victims into opening links by using Social Engineering techniques: for example, a possibility is to send an email to the target by impersonating the company IT Security Team and inviting the user to visit a url in order to download an important Security patch:.

So, when the victim visits the webpage the Java exploit executes and the attacker obtains a remote connection, i.

Attack Methods for Gaining Domain Admin Rights in Active Directory

We have an established connection between the attacker machine with IP address Choosing this port was not random: a connection of this type will be less suspicious since it mimics an ordinary SSL session like if the user is just visiting a webpage in HTTPS. Beware that this exploit works both on Internet Explorer version 8 in this test and Mozilla Firefox of course Java plugin must be active. Starting the interaction we may want to acquire system informations, like architecture, domain name, user ID and so on; sysinfo command is what we need:.

Another interesting information is given by system architecture that is bit while the meterpreter is x86, i. Before doing that, we can gather additional informations using Metasploit post exploitation modules.

attacking domain trusts

For example, it would be useful to know what kind of privileges the current user has got, like being in the Local Administrators group:. As reported the user has not Administration privileges, which means bad news for the attacker: in fact, a good Security practice is to set policies for employers workstations in such a way they do not have local Administrative privileges on their own machine of course this has also to be followed by the application of Security patches as we will see afterwards.

Enumerating Domain Admin accounts is for sure a good idea since they are interesting targets due to their privileges:.

attacking domain trusts

Remember this account, because it will be useful later. For this purpose we can analyze what Security patches are installed on the system in order to find if there are unpatched privilege escalation vulnerabilities.

The output shows clearly that in this company Windows System Administrators are not frequently updating clients workstations. For example, we have discovered that the KB to the MS vulnerability is missing, so we can exploit it. To run this module we just need to set the session on which we want to run the module on and the payload type:. This means now we have full control on the compromised system, like having access to the local stored credentials:.

This module stores gathered credential in Metasploit database so it is possible to display them with a simple command:. Analyzing collected credentials we find the following fields: a username and two strings separated by the colon symbol; these two represent the encrypted password for that user.

Windows credentials are stored using hashing algorithms: the first part of the hash represents the LAN Manager LM hash. This is why we can use the password cracking tool John The Ripper in dictionary attack mode to find the corresponding plain text password. Since NTLM hashing function is well known it is possible to compute in advance for a given word the corresponding hash; moreover it is symmetric so we have a one-to-one correspondence betweeen words and hashes.

attacking domain trusts

Once we find the one that matches, we are sure we have found the password. It is always a good idea to start with a dictionary attack instead of a brute force attack, since generally people set common words as their password and in that case we can accomplish our task pretty rapidly.

We are interested in the Administrator account, so we start by saving its details, i.Well presented article on demonstration of the ATA identification and the approach to identifying the back end and evading the same!!! I also recommend you to follow this reference on how to spy on cell phone without installing software. The week has been split in the following days:. Day 5 - Attacking ATA deployment, limitations of research and mitigation. We have seen how ATA can be bypassed and avoided during a security assessment.

Today let's see how we can attack ATA deployment. We will also discuss limitations of the research against ATA, some closing thoughts and some general mitigation against AD attacks. So how do we spot ATA? Before 1. Contains 'Microsoft Advanced Threat Analytics'. But ATA 1. But we are not out of options. We can simply look for certificate used by the ATA console.

There are a number of interesting things which can be done with it. If the ATA Center is the part of the target domain and we have escalated privileges to domain admin or have got local admin access to the Center, we can have much fun. ATA subscribes to the concept of "if its admin its game over". By default, all the members of the local administrators group local admins, domain admins on the ATA Center have administrative access to the ATA console.

We can resolve alerts, add exclusions, enumerate honey tokens etc. Use that to detect the attackers. Remember prevention is better than cure. Unknown September 3, at PM.

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