Techniques

Adversaries may reveal credentials of accounts that have disabled Kerberos preauthentication by Password Cracking Kerberos messages.[1]

Preauthentication offers protection against offline Password Cracking. When enabled, a user requesting access to a resource initiates communication with the Domain Controller (DC) by sending an Authentication Server Request (AS-REQ) message with a timestamp that is encrypted with the hash of their password. If and only if the DC is able to successfully decrypt the timestamp with the hash of the user’s password, it will then send an Authentication Server Response (AS-REP) message that contains the Ticket Granting Ticket (TGT) to the user. Part of the AS-REP message is signed with the user’s password.[2]

For each account found without preauthentication, an adversary may send an AS-REQ message without the encrypted timestamp and receive an AS-REP message with TGT data which may be encrypted with an insecure algorithm such as RC4. The recovered encrypted data may be vulnerable to offline Password Cracking attacks similarly to Kerberoasting and expose plaintext credentials. [1][3]

An account registered to a domain, with or without special privileges, can be abused to list all domain accounts that have preauthentication disabled by utilizing Windows tools like PowerShell with an LDAP filter. Alternatively, the adversary may send an AS-REQ message for each user. If the DC responds without errors, the account does not require preauthentication and the AS-REP message will already contain the encrypted data. [1][3]

Cracked hashes may enable Persistence, Privilege Escalation, and Lateral Movement via access to Valid Accounts.[4]

Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment. This information can help adversaries determine which accounts exist, which can aid in follow-on behavior such as brute-forcing, spear-phishing attacks, or account takeovers (e.g., Valid Accounts).

Adversaries may use several methods to enumerate accounts, including abuse of existing tools, built-in commands, and potential misconfigurations that leak account names and roles or permissions in the targeted environment.

For examples, cloud environments typically provide easily accessible interfaces to obtain user lists.[1][2] On hosts, adversaries can use default PowerShell and other command line functionality to identify accounts. Information about email addresses and accounts may also be extracted by searching an infected system’s files.

Adversaries may manipulate accounts to maintain and/or elevate access to victim systems. Account manipulation may consist of any action that preserves or modifies adversary access to a compromised account, such as modifying credentials or permission groups.[1] These actions could also include account activity designed to subvert security policies, such as performing iterative password updates to bypass password duration policies and preserve the life of compromised credentials.

In order to create or manipulate accounts, the adversary must already have sufficient permissions on systems or the domain. However, account manipulation may also lead to privilege escalation where modifications grant access to additional roles, permissions, or higher-privileged Valid Accounts.

Adversaries may purchase or otherwise acquire an existing access to a target system or network. A variety of online services and initial access broker networks are available to sell access to previously compromised systems.[1][2][3] In some cases, adversary groups may form partnerships to share compromised systems with each other.[4]

Footholds to compromised systems may take a variety of forms, such as access to planted backdoors (e.g., Web Shell) or established access via External Remote Services. In some cases, access brokers will implant compromised systems with a “load” that can be used to install additional malware for paying customers.[1]

By leveraging existing access broker networks rather than developing or obtaining their own initial access capabilities, an adversary can potentially reduce the resources required to gain a foothold on a target network and focus their efforts on later stages of compromise. Adversaries may prioritize acquiring access to systems that have been determined to lack security monitoring or that have high privileges, or systems that belong to organizations in a particular sector.[1][2]

In some cases, purchasing access to an organization in sectors such as IT contracting, software development, or telecommunications may allow an adversary to compromise additional victims via a Trusted Relationship, Multi-Factor Authentication Interception, or even Supply Chain Compromise.

**Note:** while this technique is distinct from other behaviors such as Purchase Technical Data and Credentials, they may often be used in conjunction (especially where the acquired foothold requires Valid Accounts).

An adversary may add additional roles or permissions to an adversary-controlled cloud account to maintain persistent access to a tenant. For example, adversaries may update IAM policies in cloud-based environments or add a new global administrator in Office 365 environments.[1][2][3][4] With sufficient permissions, a compromised account can gain almost unlimited access to data and settings (including the ability to reset the passwords of other admins).[5] [4]

This account modification may immediately follow Create Account or other malicious account activity. Adversaries may also modify existing Valid Accounts that they have compromised. This could lead to privilege escalation, particularly if the roles added allow for lateral movement to additional accounts.

For example, in AWS environments, an adversary with appropriate permissions may be able to use the CreatePolicyVersion API to define a new version of an IAM policy or the AttachUserPolicy API to attach an IAM policy with additional or distinct permissions to a compromised user account.[6]

In some cases, adversaries may add roles to adversary-controlled accounts outside the victim cloud tenant. This allows these external accounts to perform actions inside the victim tenant without requiring the adversary to Create Account or modify a victim-owned account.[7]

An adversary may add additional roles or permissions to an adversary-controlled user or service account to maintain persistent access to a container orchestration system. For example, an adversary with sufficient permissions may create a RoleBinding or a ClusterRoleBinding to bind a Role or ClusterRole to a Kubernetes account.[1][2] Where attribute-based access control (ABAC) is in use, an adversary with sufficient permissions may modify a Kubernetes ABAC policy to give the target account additional permissions.[3] This account modification may immediately follow Create Account or other malicious account activity. Adversaries may also modify existing Valid Accounts that they have compromised.

Note that where container orchestration systems are deployed in cloud environments, as with Google Kubernetes Engine, Amazon Elastic Kubernetes Service, and Azure Kubernetes Service, cloud-based role-based access control (RBAC) assignments or ABAC policies can often be used in place of or in addition to local permission assignments.[4][5][6] In these cases, this technique may be used in conjunction with Additional Cloud Roles.

Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.[1] Without knowledge of the password for an account or set of accounts, an adversary may systematically guess the password using a repetitive or iterative mechanism.[2] Brute forcing passwords can take place via interaction with a service that will check the validity of those credentials or offline against previously acquired credential data, such as password hashes.

Brute forcing credentials may take place at various points during a breach. For example, adversaries may attempt to brute force access to Valid Accounts within a victim environment leveraging knowledge gathered from other post-compromise behaviors such as OS Credential Dumping, Account Discovery, or Password Policy Discovery. Adversaries may also combine brute forcing activity with behaviors such as External Remote Services as part of Initial Access.

If an adversary guesses the correct password but fails to login to a compromised account due to location-based conditional access policies, they may change their infrastructure until they match the victim’s location and therefore bypass those policies.[3]

Valid accounts in cloud environments may allow adversaries to perform actions to achieve Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Cloud accounts are those created and configured by an organization for use by users, remote support, services, or for administration of resources within a cloud service provider or SaaS application. Cloud Accounts can exist solely in the cloud; alternatively, they may be hybrid-joined between on-premises systems and the cloud through syncing or federation with other identity sources such as Windows Active Directory.[1][2][3]

Service or user accounts may be targeted by adversaries through Brute Force, Phishing, or various other means to gain access to the environment. Federated or synced accounts may be a pathway for the adversary to affect both on-premises systems and cloud environments - for example, by leveraging shared credentials to log onto Remote Services. High privileged cloud accounts, whether federated, synced, or cloud-only, may also allow pivoting to on-premises environments by leveraging SaaS-based Software Deployment Tools to run commands on hybrid-joined devices.

An adversary may create long lasting Additional Cloud Credentials on a compromised cloud account to maintain persistence in the environment. Such credentials may also be used to bypass security controls such as multi-factor authentication.

Cloud accounts may also be able to assume Temporary Elevated Cloud Access or other privileges through various means within the environment. Misconfigurations in role assignments or role assumption policies may allow an adversary to use these mechanisms to leverage permissions outside the intended scope of the account. Such over privileged accounts may be used to harvest sensitive data from online storage accounts and databases through Cloud API or other methods. For example, in Azure environments, adversaries may target Azure Managed Identities, which allow associated Azure resources to request access tokens. By compromising a resource with an attached Managed Identity, such as an Azure VM, adversaries may be able to Steal Application Access Tokens to move laterally across the cloud environment.[4]

Adversaries may log into accessible cloud services within a compromised environment using Valid Accounts that are synchronized with or federated to on-premises user identities. The adversary may then perform management actions or access cloud-hosted resources as the logged-on user.

Many enterprises federate centrally managed user identities to cloud services, allowing users to login with their domain credentials in order to access the cloud control plane. Similarly, adversaries may connect to available cloud services through the web console or through the cloud command line interface (CLI) (e.g., Cloud API), using commands such as Connect-AZAccount for Azure PowerShell, Connect-MgGraph for Microsoft Graph PowerShell, and gcloud auth login for the Google Cloud CLI.

In some cases, adversaries may be able to authenticate to these services via Application Access Token instead of a username and password.

Adversaries may search public code repositories for information about victims that can be used during targeting. Victims may store code in repositories on various third-party websites such as GitHub, GitLab, SourceForge, and BitBucket. Users typically interact with code repositories through a web application or command-line utilities such as git.

Adversaries may search various public code repositories for various information about a victim. Public code repositories can often be a source of various general information about victims, such as commonly used programming languages and libraries as well as the names of employees. Adversaries may also identify more sensitive data, including accidentally leaked credentials or API keys.[1] Information from these sources may reveal opportunities for other forms of reconnaissance (ex: Phishing for Information), establishing operational resources (ex: Compromise Accounts or Compromise Infrastructure), and/or initial access (ex: Valid Accounts or Phishing).

**Note:** This is distinct from Code Repositories, which focuses on Collection from private and internally hosted code repositories.

Adversaries may leverage code repositories to collect valuable information. Code repositories are tools/services that store source code and automate software builds. They may be hosted internally or privately on third party sites such as Github, GitLab, SourceForge, and BitBucket. Users typically interact with code repositories through a web application or command-line utilities such as git.

Once adversaries gain access to a victim network or a private code repository, they may collect sensitive information such as proprietary source code or Unsecured Credentials contained within software's source code. Having access to software's source code may allow adversaries to develop Exploits, while credentials may provide access to additional resources using Valid Accounts.[1][2]

**Note:** This is distinct from Code Repositories, which focuses on conducting Reconnaissance via public code repositories.

Adversaries may gather credentials that can be used during targeting. Account credentials gathered by adversaries may be those directly associated with the target victim organization or attempt to take advantage of the tendency for users to use the same passwords across personal and business accounts.

Adversaries may gather credentials from potential victims in various ways, such as direct elicitation via Phishing for Information. Adversaries may also compromise sites then add malicious content designed to collect website authentication cookies from visitors.[1] [2][3][4][5][6][7][8] Where multi-factor authentication (MFA) based on out-of-band communications is in use, adversaries may compromise a service provider to gain access to MFA codes and one-time passwords (OTP).[9]

Credential information may also be exposed to adversaries via leaks to online or other accessible data sets (ex: Search Engines, breach dumps, code repositories, etc.). Adversaries may purchase credentials from dark web markets, such as Russian Market and 2easy, or through access to Telegram channels that distribute logs from infostealer malware.[10][11][12]

Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Websites/Domains or Phishing for Information), establishing operational resources (ex: Compromise Accounts), and/or initial access (ex: External Remote Services or Valid Accounts).

Adversaries may destroy data and files on specific systems or in large numbers on a network to interrupt availability to systems, services, and network resources. Data destruction is likely to render stored data irrecoverable by forensic techniques through overwriting files or data on local and remote drives.[1][2][3][4][5][6] Common operating system file deletion commands such as del and rm often only remove pointers to files without wiping the contents of the files themselves, making the files recoverable by proper forensic methodology. This behavior is distinct from Disk Content Wipe and Disk Structure Wipe because individual files are destroyed rather than sections of a storage disk or the disk's logical structure.

Adversaries may attempt to overwrite files and directories with randomly generated data to make it irrecoverable.[4][5] In some cases politically oriented image files have been used to overwrite data.[2][3][4]

To maximize impact on the target organization in operations where network-wide availability interruption is the goal, malware designed for destroying data may have worm-like features to propagate across a network by leveraging additional techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.[1][2][3][4][6].

In cloud environments, adversaries may leverage access to delete cloud storage objects, machine images, database instances, and other infrastructure crucial to operations to damage an organization or their customers.[7][8] Similarly, they may delete virtual machines from on-prem virtualized environments.

Adversaries may encrypt data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources. They can attempt to render stored data inaccessible by encrypting files or data on local and remote drives and withholding access to a decryption key. This may be done in order to extract monetary compensation from a victim in exchange for decryption or a decryption key (ransomware) or to render data permanently inaccessible in cases where the key is not saved or transmitted.[1][2][3][4]

In the case of ransomware, it is typical that common user files like Office documents, PDFs, images, videos, audio, text, and source code files will be encrypted (and often renamed and/or tagged with specific file markers). Adversaries may need to first employ other behaviors, such as File and Directory Permissions Modification or System Shutdown/Reboot, in order to unlock and/or gain access to manipulate these files.[5] In some cases, adversaries may encrypt critical system files, disk partitions, and the MBR.[3] Adversaries may also encrypt virtual machines hosted on ESXi or other hypervisors.[6]

To maximize impact on the target organization, malware designed for encrypting data may have worm-like features to propagate across a network by leveraging other attack techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.[2][3] Encryption malware may also leverage Internal Defacement, such as changing victim wallpapers or ESXi server login messages, or otherwise intimidate victims by sending ransom notes or other messages to connected printers (known as "print bombing").[7][8]

In cloud environments, storage objects within compromised accounts may also be encrypted.[9] For example, in AWS environments, adversaries may leverage services such as AWS’s Server-Side Encryption with Customer Provided Keys (SSE-C) to encrypt data.[10]

Adversaries may leverage Valid Accounts to log directly into accessible cloud hosted compute infrastructure through cloud native methods. Many cloud providers offer interactive connections to virtual infrastructure that can be accessed through the Cloud API, such as Azure Serial Console[1], AWS EC2 Instance Connect[2][3], and AWS System Manager.[4].

Methods of authentication for these connections can include passwords, application access tokens, or SSH keys. These cloud native methods may, by default, allow for privileged access on the host with SYSTEM or root level access.

Adversaries may utilize these cloud native methods to directly access virtual infrastructure and pivot through an environment.[5] These connections typically provide direct console access to the VM rather than the execution of scripts (i.e., Cloud Administration Command).

Adversaries may disable network device-based firewall mechanisms entirely or add, delete, or modify particular rules in order to bypass controls limiting network usage. Modifying or disabling a network firewall may enable adversary C2 communications, lateral movement, and/or data exfiltration that would otherwise not be allowed. For example, adversaries may add new network firewall rules to allow access to all internal network subnets without restrictions.[1]

Adversaries may gain access to the firewall management console via Valid Accounts or by exploiting a vulnerability. In some cases, threat actors may target firewalls that have been exposed to the internet Exploit Public-Facing Application.[2]

Adversaries may erase the contents of storage devices on specific systems as well as large numbers of systems in a network to interrupt availability to system and network resources.

Adversaries may partially or completely overwrite the contents of a storage device rendering the data irrecoverable through the storage interface.[1][2][3] Instead of wiping specific disk structures or files, adversaries with destructive intent may wipe arbitrary portions of disk content. To wipe disk content, adversaries may acquire direct access to the hard drive in order to overwrite arbitrarily sized portions of disk with random data.[2] Adversaries have been observed leveraging third-party drivers like RawDisk to directly access disk content.[1][2] This behavior is distinct from Data Destruction because sections of the disk erased instead of individual files.

To maximize impact on the target organization in operations where network-wide availability interruption is the goal, malware used for wiping disk content may have worm-like features to propagate across a network by leveraging additional techniques like Valid Accounts, OS Credential Dumping, and Windows Admin Shares.[2]

Adversaries may erase the contents of storage devices on specific systems or in large numbers in a network to interrupt availability to system and network resources.

Adversaries may partially or completely overwrite the contents of a storage device rendering the data irrecoverable through the storage interface.[1][2][3] Instead of wiping specific disk structures or files, adversaries with destructive intent may wipe arbitrary portions of disk content. To wipe disk content, adversaries may acquire direct access to the hard drive in order to overwrite arbitrarily sized portions of disk with random data.[2] Adversaries have also been observed leveraging third-party drivers like RawDisk to directly access disk content.[1][2] This behavior is distinct from Data Destruction because sections of the disk are erased instead of individual files.

To maximize impact on the target organization in operations where network-wide availability interruption is the goal, malware used for wiping disk content may have worm-like features to propagate across a network by leveraging additional techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.[2]

Adversaries may corrupt or wipe the disk data structures on a hard drive necessary to boot a system; targeting specific critical systems or in large numbers in a network to interrupt availability to system and network resources.

Adversaries may attempt to render the system unable to boot by overwriting critical data located in structures such as the master boot record (MBR) or partition table.[1][2][3][4][5] The data contained in disk structures may include the initial executable code for loading an operating system or the location of the file system partitions on disk. If this information is not present, the computer will not be able to load an operating system during the boot process, leaving the computer unavailable. Disk Structure Wipe may be performed in isolation, or along with Disk Content Wipe if all sectors of a disk are wiped.

On a network devices, adversaries may reformat the file system using Network Device CLI commands such as `format`.[6]

To maximize impact on the target organization, malware designed for destroying disk structures may have worm-like features to propagate across a network by leveraging other techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.[1][2][3][4]

Adversaries may corrupt or wipe the disk data structures on hard drive necessary to boot systems; targeting specific critical systems as well as a large number of systems in a network to interrupt availability to system and network resources.

Adversaries may attempt to render the system unable to boot by overwriting critical data located in structures such as the master boot record (MBR) or partition table.[1][2][3][4][5] The data contained in disk structures may include the initial executable code for loading an operating system or the location of the file system partitions on disk. If this information is not present, the computer will not be able to load an operating system during the boot process, leaving the computer unavailable. Disk Structure Wipe may be performed in isolation, or along with Disk Content Wipe if all sectors of a disk are wiped.

To maximize impact on the target organization, malware designed for destroying disk structures may have worm-like features to propagate across a network by leveraging other techniques like Valid Accounts, OS Credential Dumping, and Windows Admin Shares.[1][2][3][4]

Adversaries may wipe or corrupt raw disk data on specific systems or in large numbers in a network to interrupt availability to system and network resources. With direct write access to a disk, adversaries may attempt to overwrite portions of disk data. Adversaries may opt to wipe arbitrary portions of disk data and/or wipe disk structures like the master boot record (MBR). A complete wipe of all disk sectors may be attempted.

To maximize impact on the target organization in operations where network-wide availability interruption is the goal, malware used for wiping disks may have worm-like features to propagate across a network by leveraging additional techniques like Valid Accounts, OS Credential Dumping, and SMB/Windows Admin Shares.[1]

On network devices, adversaries may wipe configuration files and other data from the device using Network Device CLI commands such as `erase`.[2]

Adversaries may use Valid Accounts to interact with remote machines by taking advantage of Distributed Component Object Model (DCOM). The adversary may then perform actions as the logged-on user.

The Windows Component Object Model (COM) is a component of the native Windows application programming interface (API) that enables interaction between software objects, or executable code that implements one or more interfaces. Through COM, a client object can call methods of server objects, which are typically Dynamic Link Libraries (DLL) or executables (EXE). Distributed COM (DCOM) is transparent middleware that extends the functionality of COM beyond a local computer using remote procedure call (RPC) technology.[1][2]

Permissions to interact with local and remote server COM objects are specified by access control lists (ACL) in the Registry.[3] By default, only Administrators may remotely activate and launch COM objects through DCOM.[4]

Through DCOM, adversaries operating in the context of an appropriately privileged user can remotely obtain arbitrary and even direct shellcode execution through Office applications[5] as well as other Windows objects that contain insecure methods.[6][7] DCOM can also execute macros in existing documents[8] and may also invoke Dynamic Data Exchange (DDE) execution directly through a COM created instance of a Microsoft Office application[9], bypassing the need for a malicious document. DCOM can be used as a method of remotely interacting with Windows Management Instrumentation. [10]

Adversaries may gather employee names that can be used during targeting. Employee names be used to derive email addresses as well as to help guide other reconnaissance efforts and/or craft more-believable lures.

Adversaries may easily gather employee names, since they may be readily available and exposed via online or other accessible data sets (ex: Social Media or Search Victim-Owned Websites).[1] Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Websites/Domains or Phishing for Information), establishing operational resources (ex: Compromise Accounts), and/or initial access (ex: Phishing or Valid Accounts).

Adversaries will compromise and gain control of an engineering workstation for Initial Access into the control system environment. Access to an engineering workstation may occur through or physical means, such as a Valid Accounts with privileged access or infection by removable media. A dual-homed engineering workstation may allow the adversary access into multiple networks. For example, unsegregated process control, safety system, or information system networks. An Engineering Workstation is designed as a reliable computing platform that configures, maintains, and diagnoses control system equipment and applications. Compromise of an engineering workstation may provide access to, and control of, other control system applications and equipment. In the Maroochy attack, the adversary utilized a computer, possibly stolen, with proprietary engineering software to communicate with a wastewater system.

Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management and VNC can also be used externally.[1]

Access to Valid Accounts to use the service is often a requirement, which could be obtained through credential pharming or by obtaining the credentials from users after compromising the enterprise network.[2] Access to remote services may be used as a redundant or persistent access mechanism during an operation.

Access may also be gained through an exposed service that doesn’t require authentication. In containerized environments, this may include an exposed Docker API, Kubernetes API server, kubelet, or web application such as the Kubernetes dashboard.[3][4]

Adversaries may also establish persistence on network by configuring a Tor hidden service on a compromised system. Adversaries may utilize the tool `ShadowLink` to facilitate the installation and configuration of the Tor hidden service. Tor hidden service is then accessible via the Tor network because `ShadowLink` sets up a .onion address on the compromised system. `ShadowLink` may be used to forward any inbound connections to RDP, allowing the adversaries to have remote access.[5] Adversaries may get `ShadowLink` to persist on a system by masquerading it as an MS Defender application.[6]