Techniques

Adversaries may register a device to an adversary-controlled account. Devices may be registered in a multifactor authentication (MFA) system, which handles authentication to the network, or in a device management system, which handles device access and compliance.

MFA systems, such as Duo or Okta, allow users to associate devices with their accounts in order to complete MFA requirements. An adversary that compromises a user’s credentials may enroll a new device in order to bypass initial MFA requirements and gain persistent access to a network.[1][2] In some cases, the MFA self-enrollment process may require only a username and password to enroll the account's first device or to enroll a device to an inactive account. [3]

Similarly, an adversary with existing access to a network may register a device or a virtual machine to Entra ID and/or its device management system, Microsoft Intune, in order to access sensitive data or resources while bypassing conditional access policies.[4][5][6][7]

Devices registered in Entra ID may be able to conduct Internal Spearphishing campaigns via intra-organizational emails, which are less likely to be treated as suspicious by the email client.[8] Additionally, an adversary may be able to perform a Service Exhaustion Flood on an Entra ID tenant by registering a large number of devices.[9]

Adversaries may search public digital certificate data for information about victims that can be used during targeting. Digital certificates are issued by a certificate authority (CA) in order to cryptographically verify the origin of signed content. These certificates, such as those used for encrypted web traffic (HTTPS SSL/TLS communications), contain information about the registered organization such as name and location.

Adversaries may search digital certificate data to gather actionable information. Threat actors can use online resources and lookup tools to harvest information about certificates.[1] Digital certificate data may also be available from artifacts signed by the organization (ex: certificates used from encrypted web traffic are served with content).[2] Information from these sources may reveal opportunities for other forms of reconnaissance (ex: Active Scanning or Phishing for Information), establishing operational resources (ex: Develop Capabilities or Obtain Capabilities), and/or initial access (ex: External Remote Services or Trusted Relationship).

Adversaries may gather information about the victim's network domain(s) that can be used during targeting. Information about domains and their properties may include a variety of details, including what domain(s) the victim owns as well as administrative data (ex: name, registrar, etc.) and more directly actionable information such as contacts (email addresses and phone numbers), business addresses, and name servers.

Adversaries may gather this information in various ways, such as direct collection actions via Active Scanning or Phishing for Information. Information about victim domains and their properties may also be exposed to adversaries via online or other accessible data sets (ex: WHOIS).[1][2][3] Where third-party cloud providers are in use, this information may also be exposed through publicly available API endpoints, such as GetUserRealm and autodiscover in Office 365 environments.[4][5] Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Technical Databases, Search Open Websites/Domains, or Phishing for Information), establishing operational resources (ex: Acquire Infrastructure or Compromise Infrastructure), and/or initial access (ex: Phishing).

Adversaries may acquire domains that can be used during targeting. Domain names are the human readable names used to represent one or more IP addresses. They can be purchased or, in some cases, acquired for free.

Adversaries may use acquired domains for a variety of purposes, including for Phishing, Drive-by Compromise, and Command and Control.[1] Adversaries may choose domains that are similar to legitimate domains, including through use of homoglyphs or use of a different top-level domain (TLD).[2][3] Typosquatting may be used to aid in delivery of payloads via Drive-by Compromise. Adversaries may also use internationalized domain names (IDNs) and different character sets (e.g. Cyrillic, Greek, etc.) to execute "IDN homograph attacks," creating visually similar lookalike domains used to deliver malware to victim machines.[4][5][6][7][8]

Different URIs/URLs may also be dynamically generated to uniquely serve malicious content to victims (including one-time, single use domain names).[9][10][11][12]

Adversaries may also acquire and repurpose expired domains, which may be potentially already allowlisted/trusted by defenders based on an existing reputation/history.[13][14][15][16]

Domain registrars each maintain a publicly viewable database that displays contact information for every registered domain. Private WHOIS services display alternative information, such as their own company data, rather than the owner of the domain. Adversaries may use such private WHOIS services to obscure information about who owns a purchased domain. Adversaries may further interrupt efforts to track their infrastructure by using varied registration information and purchasing domains with different domain registrars.[17]

In addition to legitimately purchasing a domain, an adversary may register a new domain in a compromised environment. For example, in AWS environments, adversaries may leverage the Route53 domain service to register a domain and create hosted zones pointing to resources of the threat actor’s choosing.[18]

Adversaries may abuse a double extension in the filename as a means of masquerading the true file type. A file name may include a secondary file type extension that may cause only the first extension to be displayed (ex: File.txt.exe may render in some views as just File.txt). However, the second extension is the true file type that determines how the file is opened and executed. The real file extension may be hidden by the operating system in the file browser (ex: explorer.exe), as well as in any software configured using or similar to the system’s policies.[1][2]

Adversaries may abuse double extensions to attempt to conceal dangerous file types of payloads. A very common usage involves tricking a user into opening what they think is a benign file type but is actually executable code. Such files often pose as email attachments and allow an adversary to gain Initial Access into a user’s system via Spearphishing Attachment then User Execution. For example, an executable file attachment named Evil.txt.exe may display as Evil.txt to a user. The user may then view it as a benign text file and open it, inadvertently executing the hidden malware.[2]

Common file types, such as text files (.txt, .doc, etc.) and image files (.jpg, .gif, etc.) are typically used as the first extension to appear benign. Executable extensions commonly regarded as dangerous, such as .exe, .lnk, .hta, and .scr, often appear as the second extension and true file type.

Adversaries may use Windows Dynamic Data Exchange (DDE) to execute arbitrary commands. DDE is a client-server protocol for one-time and/or continuous inter-process communication (IPC) between applications. Once a link is established, applications can autonomously exchange transactions consisting of strings, warm data links (notifications when a data item changes), hot data links (duplications of changes to a data item), and requests for command execution.

Object Linking and Embedding (OLE), or the ability to link data between documents, was originally implemented through DDE. Despite being superseded by Component Object Model, DDE may be enabled in Windows 10 and most of Microsoft Office 2016 via Registry keys.[1][2][3]

Microsoft Office documents can be poisoned with DDE commands, directly or through embedded files, and used to deliver execution via Phishing campaigns or hosted Web content, avoiding the use of Visual Basic for Applications (VBA) macros.[4][5][6][7] Similarly, adversaries may infect payloads to execute applications and/or commands on a victim device by way of embedding DDE formulas within a CSV file intended to be opened through a Windows spreadsheet program.[8][9]

DDE could also be leveraged by an adversary operating on a compromised machine who does not have direct access to a Command and Scripting Interpreter. DDE execution can be invoked remotely via Remote Services such as Distributed Component Object Model (DCOM).[10]

Adversaries may compromise email accounts that can be used during targeting. Adversaries can use compromised email accounts to further their operations, such as leveraging them to conduct Phishing for Information, Phishing, or large-scale spam email campaigns. Utilizing an existing persona with a compromised email account may engender a level of trust in a potential victim if they have a relationship with, or knowledge of, the compromised persona. Compromised email accounts can also be used in the acquisition of infrastructure (ex: Domains).

A variety of methods exist for compromising email accounts, such as gathering credentials via Phishing for Information, purchasing credentials from third-party sites, brute forcing credentials (ex: password reuse from breach credential dumps), or paying employees, suppliers or business partners for access to credentials.[1][2] Prior to compromising email accounts, adversaries may conduct Reconnaissance to inform decisions about which accounts to compromise to further their operation. Adversaries may target compromising well-known email accounts or domains from which malicious spam or Phishing emails may evade reputation-based email filtering rules.

Adversaries can use a compromised email account to hijack existing email threads with targets of interest.

Adversaries may create email accounts that can be used during targeting. Adversaries can use accounts created with email providers to further their operations, such as leveraging them to conduct Phishing for Information or Phishing.[1] Establishing email accounts may also allow adversaries to abuse free services – such as trial periods – to Acquire Infrastructure for follow-on purposes.[2]

Adversaries may also take steps to cultivate a persona around the email account, such as through use of Social Media Accounts, to increase the chance of success of follow-on behaviors. Created email accounts can also be used in the acquisition of infrastructure (ex: Domains).[1]

To decrease the chance of physically tying back operations to themselves, adversaries may make use of disposable email services.[3]

Adversaries may gather email addresses that can be used during targeting. Even if internal instances exist, organizations may have public-facing email infrastructure and addresses for employees.

Adversaries may easily gather email addresses, since they may be readily available and exposed via online or other accessible data sets (ex: Social Media or Search Victim-Owned Websites).[1][2] Email addresses could also be enumerated via more active means (i.e. Active Scanning), such as probing and analyzing responses from authentication services that may reveal valid usernames in a system.[3] For example, adversaries may be able to enumerate email addresses in Office 365 environments by querying a variety of publicly available API endpoints, such as autodiscover and GetCredentialType.[4][5]

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

Adversaries may flood targeted email addresses with an overwhelming volume of messages. This may bury legitimate emails in a flood of spam and disrupt business operations.[1][2]

An adversary may accomplish email bombing by leveraging an automated bot to register a targeted address for e-mail lists that do not validate new signups, such as online newsletters. The result can be a wave of thousands of e-mails that effectively overloads the victim’s inbox.[2][3]

By sending hundreds or thousands of e-mails in quick succession, adversaries may successfully divert attention away from and bury legitimate messages including security alerts, daily business processes like help desk tickets and client correspondence, or ongoing scams.[3] This behavior can also be used as a tool of harassment.[2]

This behavior may be a precursor for Spearphishing Voice. For example, an adversary may email bomb a target and then follow up with a phone call to fraudulently offer assistance. This social engineering may lead to the use of Remote Access Software to steal credentials, deploy ransomware, conduct Financial Theft[1], or engage in other malicious activity.[4]

Adversaries may use email rules to hide inbound emails in a compromised user's mailbox. Many email clients allow users to create inbox rules for various email functions, including moving emails to other folders, marking emails as read, or deleting emails. Rules may be created or modified within email clients or through external features such as the New-InboxRule or Set-InboxRule PowerShell cmdlets on Windows systems.[1][2][3][4]

Adversaries may utilize email rules within a compromised user's mailbox to delete and/or move emails to less noticeable folders. Adversaries may do this to hide security alerts, C2 communication, or responses to Internal Spearphishing emails sent from the compromised account.

Any user or administrator within the organization (or adversary with valid credentials) may be able to create rules to automatically move or delete emails. These rules can be abused to impair/delay detection had the email content been immediately seen by a user or defender. Malicious rules commonly filter out emails based on key words (such as malware, suspicious, phish, and hack) found in message bodies and subject lines. [5]

In some environments, administrators may be able to enable email rules that operate organization-wide rather than on individual inboxes. For example, Microsoft Exchange supports transport rules that evaluate all mail an organization receives against user-specified conditions, then performs a user-specified action on mail that adheres to those conditions.[6] Adversaries that abuse such features may be able to automatically modify or delete all emails related to specific topics (such as internal security incident notifications).

Adversaries may fake, or spoof, a sender’s identity by modifying the value of relevant email headers in order to establish contact with victims under false pretenses.[1] In addition to actual email content, email headers (such as the FROM header, which contains the email address of the sender) may also be modified. Email clients display these headers when emails appear in a victim's inbox, which may cause modified emails to appear as if they were from the spoofed entity.

Enterprise environments can use Domain-based Message Authentication, Reporting, and Conformance (DMARC) as an email authentication protocol that references results of the Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) configurations. SPF and DKIM are configured separately in DNS: SPF verifies that the sending server is authorized for the domain, while DKIM uses a digital signature to verify email integrity and domain authentication. Together, they validate email authenticity and specify how receiving servers should handle authentication failures. Without enforced identity authentication, adversaries may compromise the integrity of an authentication check with altered headers that would not have otherwise passed.[2][3][4]

An example of a weak or absent DMARC policy is `v=DMARC1; p=none; fo=1;`. The `p=none`. The `p=none` indicates no action should be taken, and therefore no filtering action will take place, even if an email fails authentication checks (i.e., SPF and/or DKIM fail). When a DMARC policy indicates no action, the email will still be delivered to the victim’s inbox.[5]

Adversaries have abused weak or absent DMARC policies to circumvent authentication checks and conceal social engineering attempts. Adversaries can alter email headers to include legitimate domain names with fake usernames or impersonate legitimate users via Impersonation for Phishing. Additionally, adversaries may abuse Microsoft 365’s Direct Send functionality to spoof internal users by using internal devices like printers to send emails without authentication.[6]

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 may encrypt or encode files to obfuscate strings, bytes, and other specific patterns to impede detection. Encrypting and/or encoding file content aims to conceal malicious artifacts within a file used in an intrusion. Many other techniques, such as Software Packing, Steganography, and Embedded Payloads, share this same broad objective. Encrypting and/or encoding files could lead to a lapse in detection of static signatures, only for this malicious content to be revealed (i.e., Deobfuscate/Decode Files or Information) at the time of execution/use.

This type of file obfuscation can be applied to many file artifacts present on victim hosts, such as malware log/configuration and payload files.[1] Files can be encrypted with a hardcoded or user-supplied key, as well as otherwise obfuscated using standard encoding schemes such as Base64.

The entire content of a file may be obfuscated, or just specific functions or values (such as C2 addresses). Encryption and encoding may also be applied in redundant layers for additional protection.

For example, adversaries may abuse password-protected Word documents or self-extracting (SFX) archives as a method of encrypting/encoding a file such as a Phishing payload. These files typically function by attaching the intended archived content to a decompressor stub that is executed when the file is invoked (e.g., User Execution).[2]

Adversaries may also abuse file-specific as well as custom encoding schemes. For example, Byte Order Mark (BOM) headers in text files may be abused to manipulate and obfuscate file content until Command and Scripting Interpreter execution.

Adversaries may create and cultivate accounts with services that can be used during targeting. Adversaries can create accounts that can be used to build a persona to further operations. Persona development consists of the development of public information, presence, history and appropriate affiliations. This development could be applied to social media, website, or other publicly available information that could be referenced and scrutinized for legitimacy over the course of an operation using that persona or identity.[1][2]

For operations incorporating social engineering, the utilization of an online persona may be important. These personas may be fictitious or impersonate real people. The persona may exist on a single site or across multiple sites (ex: Facebook, LinkedIn, Twitter, Google, GitHub, Docker Hub, etc.). Establishing a persona may require development of additional documentation to make them seem real. This could include filling out profile information, developing social networks, or incorporating photos.[1][2]

Establishing accounts can also include the creation of accounts with email providers, which may be directly leveraged for Phishing for Information or Phishing.[3] In addition, establishing accounts may allow adversaries to abuse free services, such as registering for trial periods to Acquire Infrastructure for malicious purposes.[4]

Adversaries may exploit software vulnerabilities in client applications to execute code. Vulnerabilities can exist in software due to unsecure coding practices that can lead to unanticipated behavior. Adversaries can take advantage of certain vulnerabilities through targeted exploitation for the purpose of arbitrary code execution. Oftentimes the most valuable exploits to an offensive toolkit are those that can be used to obtain code execution on a remote system because they can be used to gain access to that system. Users will expect to see files related to the applications they commonly used to do work, so they are a useful target for exploit research and development because of their high utility.

Several types exist:

### Browser-based Exploitation

Web browsers are a common target through Drive-by Compromise and Spearphishing Link. Endpoint systems may be compromised through normal web browsing or from certain users being targeted by links in spearphishing emails to adversary controlled sites used to exploit the web browser. These often do not require an action by the user for the exploit to be executed.

### Office Applications

Common office and productivity applications such as Microsoft Office are also targeted through Phishing. Malicious files will be transmitted directly as attachments or through links to download them. These require the user to open the document or file for the exploit to run.

### Common Third-party Applications

Other applications that are commonly seen or are part of the software deployed in a target network may also be used for exploitation. Applications such as Adobe Reader and Flash, which are common in enterprise environments, have been routinely targeted by adversaries attempting to gain access to systems. Depending on the software and nature of the vulnerability, some may be exploited in the browser or require the user to open a file. For instance, some Flash exploits have been delivered as objects within Microsoft Office documents.

Adversaries may exploit software vulnerabilities in client applications to execute code. Vulnerabilities can exist in software due to insecure coding practices that can lead to unanticipated behavior. Adversaries may take advantage of certain vulnerabilities through targeted exploitation for the purpose of arbitrary code execution. Oftentimes the most valuable exploits to an offensive toolkit are those that can be used to obtain code execution on a remote system because they can be used to gain access to that system. Users will expect to see files related to the applications they commonly used to do work, so they are a useful target for exploit research and development because of their high utility.

Adversaries may use device-based zero-click exploits for code execution. These exploits are powerful because there is no user interaction required for code execution.

### SMS/iMessage Delivery

SMS and iMessage in iOS are common targets through Drive-By Compromise, Phishing, etc. Adversaries may use embed malicious links, files, etc. in SMS messages or iMessages. Mobile devices may be compromised through one-click exploits, where the victim must interact with a text message, or zero-click exploits, where no user interaction is required.

### AirDrop

Unique to iOS, AirDrop is a network protocol that allows iOS users to transfer files between iOS devices. Before patches from Apple were released, on iOS 13.4 and earlier, adversaries may force the Apple Wireless Direct Link (AWDL) interface to activate, then exploit a buffer overflow to gain access to the device and run as root without interaction from the user.

Adversaries may exploit vulnerabilities in security software, infrastructure, or defensive components to degrade, disable, or otherwise continue to impair their ability to prevent, detect, or respond to malicious activity. Adversaries may exploit a system or application vulnerability to directly interfere with defensive mechanisms. Exploitation occurs when an adversary takes advantage of a programming error in software, services, or the operating system to execute adversary-controlled code, often with the goal of weakening or disabling protections.

Vulnerabilities may exist in security tools such as antivirus, endpoint detection and response (EDR), firewalls, or other monitoring solutions. Adversaries may use prior reconnaissance or perform discovery activities (e.g., Software Discovery) to identify defensive tools present in an environment and target them for exploitation.

Successful exploitation may allow adversaries to terminate security processes, disable protections, bypass enforcement mechanisms, or reduce the effectiveness of defensive controls. In some cases, vulnerabilities in cloud-based or SaaS infrastructure may also be leveraged to bypass built-in security boundaries or disrupt visibility and enforcement across environments.[1]

Adversaries may gather information about the victim's host firmware that can be used during targeting. Information about host firmware may include a variety of details such as type and versions on specific hosts, which may be used to infer more information about hosts in the environment (ex: configuration, purpose, age/patch level, etc.).

Adversaries may gather this information in various ways, such as direct elicitation via Phishing for Information. Information about host firmware may only be exposed to adversaries via online or other accessible data sets (ex: job postings, network maps, assessment reports, resumes, or purchase invoices).[1] Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Websites/Domains or Search Open Technical Databases), establishing operational resources (ex: Develop Capabilities or Obtain Capabilities), and/or initial access (ex: Supply Chain Compromise or Exploit Public-Facing Application).

Adversaries may gather credential material by invoking or forcing a user to automatically provide authentication information through a mechanism in which they can intercept.

The Server Message Block (SMB) protocol is commonly used in Windows networks for authentication and communication between systems for access to resources and file sharing. When a Windows system attempts to connect to an SMB resource it will automatically attempt to authenticate and send credential information for the current user to the remote system.[1] This behavior is typical in enterprise environments so that users do not need to enter credentials to access network resources.

Web Distributed Authoring and Versioning (WebDAV) is also typically used by Windows systems as a backup protocol when SMB is blocked or fails. WebDAV is an extension of HTTP and will typically operate over TCP ports 80 and 443.[2][3]

Adversaries may take advantage of this behavior to gain access to user account hashes through forced SMB/WebDAV authentication. An adversary can send an attachment to a user through spearphishing that contains a resource link to an external server controlled by the adversary (i.e. Template Injection), or place a specially crafted file on navigation path for privileged accounts (e.g. .SCF file placed on desktop) or on a publicly accessible share to be accessed by victim(s). When the user's system accesses the untrusted resource, it will attempt authentication and send information, including the user's hashed credentials, over SMB to the adversary-controlled server.[4] With access to the credential hash, an adversary can perform off-line Brute Force cracking to gain access to plaintext credentials.[5]

There are several different ways this can occur.[6] Some specifics from in-the-wild use include:

* A spearphishing attachment containing a document with a resource that is automatically loaded when the document is opened (i.e. Template Injection). The document can include, for example, a request similar to file[:]//[remote address]/Normal.dotm to trigger the SMB request.[7] * A modified .LNK or .SCF file with the icon filename pointing to an external reference such as \\[remote address]\pic.png that will force the system to load the resource when the icon is rendered to repeatedly gather credentials.[7]

Alternatively, by leveraging the EfsRpcOpenFileRaw function, an adversary can send SMB requests to a remote system's MS-EFSRPC interface and force the victim computer to initiate an authentication procedure and share its authentication details. The Encrypting File System Remote Protocol (EFSRPC) is a protocol used in Windows networks for maintenance and management operations on encrypted data that is stored remotely to be accessed over a network. Utilization of EfsRpcOpenFileRaw function in EFSRPC is used to open an encrypted object on the server for backup or restore. Adversaries can collect this data and abuse it as part of a NTLM relay attack to gain access to remote systems on the same internal network.[8][9]

Adversaries may mimic common operating system GUI components to prompt users for credentials with a seemingly legitimate prompt. When programs are executed that need additional privileges than are present in the current user context, it is common for the operating system to prompt the user for proper credentials to authorize the elevated privileges for the task (ex: Bypass User Account Control).

Adversaries may mimic this functionality to prompt users for credentials with a seemingly legitimate prompt for a number of reasons that mimic normal usage, such as a fake installer requiring additional access or a fake malware removal suite.[1] This type of prompt can be used to collect credentials via various languages such as AppleScript[2][3][4] and PowerShell.[2][5][4] On Linux systems adversaries may launch dialog boxes prompting users for credentials from malicious shell scripts or the command line (i.e. Unix Shell).[4]

Adversaries may also mimic common software authentication requests, such as those from browsers or email clients. This may also be paired with user activity monitoring (i.e., Browser Information Discovery and/or Application Window Discovery) to spoof prompts when users are naturally accessing sensitive sites/data.

Adversaries may mimic common operating system GUI components to prompt users for sensitive information with a seemingly legitimate prompt. The operating system and installed applications often have legitimate needs to prompt the user for sensitive information such as account credentials, bank account information, or Personally Identifiable Information (PII). Compared to traditional PCs, the constrained display size of mobile devices may impair the ability to provide users with contextual information, making users more susceptible to this technique’s use.[1]

There are several approaches adversaries may use to mimic this functionality. Adversaries may impersonate the identity of a legitimate application (e.g. use the same application name and/or icon) and, when installed on the device, may prompt the user for sensitive information.[2] Adversaries may also send fake device notifications to the user that may trigger the display of an input prompt when clicked.[3]

Additionally, adversaries may display a prompt on top of a running, legitimate application to trick users into entering sensitive information into a malicious application rather than the legitimate application. Typically, adversaries need to know when the targeted application and the individual activity within the targeted application is running in the foreground to display the prompt at the proper time. Adversaries can abuse Android’s accessibility features to determine which application is currently in the foreground.[4] Two known approaches to displaying a prompt include:

* Adversaries start a new activity on top of a running legitimate application.[1][5] Android 10 places new restrictions on the ability for an application to start a new activity on top of another application, which may make it more difficult for adversaries to utilize this technique.[6] * Adversaries create an application overlay window on top of a running legitimate application. Applications must hold the `SYSTEM_ALERT_WINDOW` permission to create overlay windows. This permission is handled differently than typical Android permissions and, at least under certain conditions, is automatically granted to applications installed from the Google Play Store.[7][8][9] The `SYSTEM_ALERT_WINDOW` permission and its associated ability to create application overlay windows are expected to be deprecated in a future release of Android in favor of a new API.[10]

Adversaries may gather information about the victim's hosts that can be used during targeting. Information about hosts may include a variety of details, including administrative data (ex: name, assigned IP, functionality, etc.) as well as specifics regarding its configuration (ex: operating system, language, etc.).

Adversaries may gather this information in various ways, such as direct collection actions via Active Scanning or Phishing for Information. Adversaries may also compromise sites then include malicious content designed to collect host information from visitors.[1] Information about hosts may also be exposed to adversaries via online or other accessible data sets (ex: Social Media or Search Victim-Owned Websites). Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Websites/Domains or Search Open Technical Databases), establishing operational resources (ex: Develop Capabilities or Obtain Capabilities), and/or initial access (ex: Supply Chain Compromise or External Remote Services).

Adversaries may also gather victim host information via User-Agent HTTP headers, which are sent to a server to identify the application, operating system, vendor, and/or version of the requesting user agent. This can be used to inform the adversary’s follow-on action. For example, adversaries may check user agents for the requesting operating system, then only serve malware for target operating systems while ignoring others.[2]

Adversaries may gather information about the victim's identity that can be used during targeting. Information about identities may include a variety of details, including personal data (ex: employee names, email addresses, security question responses, etc.) as well as sensitive details such as credentials or multi-factor authentication (MFA) configurations.

Adversaries may gather this information in various ways, such as direct elicitation via Phishing for Information. Information about users could also be enumerated via other active means (i.e. Active Scanning) such as probing and analyzing responses from authentication services that may reveal valid usernames in a system or permitted MFA /methods associated with those usernames.[1][2] Information about victims may also be exposed to adversaries via online or other accessible data sets (ex: Social Media or Search Victim-Owned Websites).[3][4][5][6][7][8][9][10]

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 may gather information about the victim's networks that can be used during targeting. Information about networks may include a variety of details, including administrative data (ex: IP ranges, domain names, etc.) as well as specifics regarding its topology and operations.

Adversaries may gather this information in various ways, such as direct collection actions via Active Scanning or Phishing for Information. Information about networks may also be exposed to adversaries via online or other accessible data sets (ex: Search Open Technical Databases).[1][2][3] Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Active Scanning or Search Open Websites/Domains), establishing operational resources (ex: Acquire Infrastructure or Compromise Infrastructure), and/or initial access (ex: Trusted Relationship).