Governance & Risk

An access control approach in which access is mediated based on attributes associated with subjects (requesters) and the objects to be accessed. Each object and subject has a set of associated attributes, such as location, time of creation, access rights, etc. Access to an object is authorized or denied depending upon whether the required (e.g., policy defined) correlation can be made between the attributes of that object and of the requesting subject.

The process of granting or denying specific requests to 1) obtain and use information and related information processing services and 2) enter specific physical facilities (e.g., federal buildings, military establishments, border crossing entrances).

Level of residual risk to the organization’s operations, assets, or individuals that falls within the defined risk appetite and risk tolerance by the organization.

Access control is the set of mechanisms and policies used to restrict access to resources and enforce authorization decisions.

A mechanism that implements access control for a system resource by enumerating the identities of the system entities that are permitted to access the resources.

A table in which each row represents a subject, each column represents an object, and each entry is the set of access rights for that subject to that object.

Implementations of formal AC policy such as AC model. Access control mechanisms can be designed to adhere to the properties of the model by machine implementation using protocols, architecture, or formal languages such as program code.

Formal presentations of the security policies enforced by AC systems, and are useful for proving theoretical limitations of systems. AC models bridge the gap in abstraction between policy and mechanism.

an access control paradigm whereby access rights are granted to users through the use of policies which combine attributes together. The policies can use any type of attributes (user attributes, resource attributes, environment attribute etc.

A set of procedures and/or processes, normally automated, which allows access to a controlled area or to information to be controlled, in accordance with pre established policies and rules.

Access Management is the set of practices that enables only those permitted the ability to perform an action on a particular resource. The three most common Access Management services you encounter every day perhaps without realizing it are: Policy Administration, Authentication, and Authorization.

The principle that an individual is entrusted to safeguard and control equipment, keying material, and information and is answerable to proper authority for the loss or misuse of that equipment or information.

A numeric code used to indicate the minimum accounting controls required for items of accountable COMSEC material within the COMSEC material control system (CMCS).

The official management decision given by a senior agency official to authorize operation of an information system and to explicitly accept the risk to agency operations (including mission, functions, image, or reputation), agency assets, or individuals, based on the implementation of an agreed upon set of security controls.

A senior (federal) official or executive with the authority to formally assume responsibility for operating an information system at an acceptable level of risk to organizational operations (including mission, functions, image, or reputation), organizational assets, individuals, other organizations, and the Nation.

A list of entities, together with their access rights, that are authorized to have access to a resource.

Implementations of formal AC policy such as AC model. Access control mechanisms can be designed to adhere to the properties of the model by machine implementation using protocols, architecture, or formal languages such as program code.

High level requirements that specify how access is managed and who may access information under what circumstances.

The risk remaining after management has taken action to alter its severity.

A device for moving or controlling a mechanism or system. It is operated by a source of energy, typically electric current, hydraulic fluid pressure, or pneumatic pressure, and converts that energy into motion. An actuator is the mechanism by which a control system acts upon an environment. The control system can be simple (a fixed mechanical or electronic system), software based (e.g., a printer driver, robot control system), or a human or other agent.

Security commensurate with the risk and the magnitude of harm resulting from the loss, misuse, or unauthorized access to or modification of information.

Routes that the BGP router will advertise, based on its local policy, to its peers.

Adversaries may use bootkits to persist on systems. A bootkit is a malware variant that modifies the boot sectors of a hard drive, allowing malicious code to execute before a computer's operating system has loaded. Bootkits reside at a layer below the operating system and may make it difficult to perform full remediation unless an organization suspects one was used and can act accordingly.

Adversaries may bypass UAC mechanisms to elevate process privileges on system. Windows User Account Control (UAC) allows a program to elevate its privileges (tracked as integrity levels ranging from low to high) to perform a task under administrator level permissions, possibly by prompting the user for confirmation. The impact to the user ranges from denying the operation under high enforcement to allowing the user to perform the action if they are in the local administrators group and click through the prompt or allowing them to enter an administrator password to complete the action.(Citation: TechNet How UAC Works)

Confidentiality is the property that information is not disclosed to unauthorized parties.

Adversaries may collect data related to managed devices from configuration repositories. Configuration repositories are used by management systems in order to configure, manage, and control data on remote systems. Configuration repositories may also facilitate remote access and administration of devices.

Adversaries may attempt to cause a denial of service (DoS) by directly sending a high volume of network traffic to a target. This DoS attack may also reduce the availability and functionality of the targeted system(s) and network. Direct Network Floods are when one or more systems are used to send a high volume of network packets towards the targeted service's network. Almost any network protocol may be used for flooding. Stateless protocols such as UDP or ICMP are commonly used but stateful protocols such as TCP can be used as well.

Adversaries may gather information about the victim's DNS that can be used during targeting. DNS information may include a variety of details, including registered name servers as well as records that outline addressing for a target’s subdomains, mail servers, and other hosts. DNS MX, TXT, and SPF records may also reveal the use of third party cloud and SaaS providers, such as Office 365, G Suite, Salesforce, or Zendesk.(Citation: Sean Metcalf Twitter DNS Records)

Adversaries may set up their own Domain Name System (DNS) servers that can be used during targeting. During post compromise activity, adversaries may utilize DNS traffic for various tasks, including for Command and Control (ex: Application Layer Protocol). Instead of hijacking existing DNS servers, adversaries may opt to configure and run their own DNS servers in support of operations.

Adversaries may make use of Domain Generation Algorithms (DGAs) to dynamically identify a destination domain for command and control traffic rather than relying on a list of static IP addresses or domains. This has the advantage of making it much harder for defenders to block, track, or take over the command and control channel, as there potentially could be thousands of domains that malware can check for instructions.(Citation: Cybereason Dissecting DGAs)(Citation: Cisco Umbrella DGA)(Citation: Unit 42 DGA Feb 2019)

Adversaries may inject malicious code into process via Extra Window Memory (EWM) in order to evade process based defenses as well as possibly elevate privileges. EWM injection is a method of executing arbitrary code in the address space of a separate live process.

Adversaries may gather information on Group Policy settings to identify paths for privilege escalation, security measures applied within a domain, and to discover patterns in domain objects that can be manipulated or used to blend in the environment. Group Policy allows for centralized management of user and computer settings in Active Directory (AD). Group policy objects (GPOs) are containers for group policy settings made up of files stored within a predictable network path .(Citation: TechNet Group Policy Basics)(Citation: ADSecurity GPO Persistence 2016)

Adversaries may abuse various implementations of JavaScript for execution. JavaScript (JS) is a platform independent scripting language (compiled just in time at runtime) commonly associated with scripts in webpages, though JS can be executed in runtime environments outside the browser.(Citation: NodeJS)

Least privilege means granting only the minimum access necessary to perform an authorized task.

Adversaries may modify the lifecycle policies of a cloud storage bucket to destroy all objects stored within.

Adversaries may modify file or directory permissions/attributes to evade access control lists (ACLs) and access protected files.(Citation: Hybrid Analysis Icacls1 June 2018)(Citation: Hybrid Analysis Icacls2 May 2018) File and directory permissions are commonly managed by ACLs configured by the file or directory owner, or users with the appropriate permissions. File and directory ACL implementations vary by platform, but generally explicitly designate which users or groups can perform which actions (read, write, execute, etc.).

Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.(Citation: Passcape LSA Secrets)(Citation: Microsoft AD Admin Tier Model)(Citation: Tilbury Windows Credentials) LSA secrets are stored in the registry at <code HKEY LOCAL MACHINE\SECURITY\Policy\Secrets</code . LSA secrets can also be dumped from memory.(Citation: ired Dumping LSA Secrets)

Adversaries may purchase online advertisements that can be abused to distribute malware to victims. Ads can be purchased to plant as well as favorably position artifacts in specific locations online, such as prominently placed within search engine results. These ads may make it more difficult for users to distinguish between actual search results and advertisements.(Citation: spamhaus malvertising) Purchased ads may also target specific audiences using the advertising network’s capabilities, potentially further taking advantage of the trust inherently given to search engines and popular websites.

MFA stands for Multi factor Authentication, an authentication method using multiple factors.

Adversaries may attempt to modify hierarchical structures in infrastructure as a service (IaaS) environments in order to evade defenses.

Adversaries may compromise third party network devices that can be used during targeting. Network devices, such as small office/home office (SOHO) routers, may be compromised where the adversary's ultimate goal is not Initial Access to that environment, but rather to leverage these devices to support additional targeting.

Adversaries may use PubPrn to proxy execution of malicious remote files. PubPrn.vbs is a Visual Basic script that publishes a printer to Active Directory Domain Services. The script may be signed by Microsoft and is commonly executed through the Windows Command Shell via <code Cscript.exe</code . For example, the following code publishes a printer within the specified domain: <code cscript pubprn Printer1 LDAP://CN=Container1,DC=Domain1,DC=Com</code .(Citation: pubprn)

Adversaries may abuse rundll32.exe to proxy execution of malicious code. Using rundll32.exe, vice executing directly (i.e. Shared Modules), may avoid triggering security tools that may not monitor execution of the rundll32.exe process because of allowlists or false positives from normal operations. Rundll32.exe is commonly associated with executing DLL payloads (ex: <code rundll32.exe {DLLname, DLLfunction}</code ).

Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel.(Citation: Stack Overflow) In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet , which leverages WMI class to create a scheduled task via an XML path.(Citation: Red Canary Atomic Red Team)

Adversaries may purchase and configure serverless cloud infrastructure, such as Cloudflare Workers, AWS Lambda functions, or Google Apps Scripts, that can be used during targeting. By utilizing serverless infrastructure, adversaries can make it more difficult to attribute infrastructure used during operations back to them.

Adversaries may execute their own malicious payloads by hijacking the Registry entries used by services. Flaws in the permissions for Registry keys related to services can allow adversaries to redirect the originally specified executable to one they control, launching their own code when a service starts. Windows stores local service configuration information in the Registry under <code HKLM\SYSTEM\CurrentControlSet\Services</code . The information stored under a service's Registry keys can be manipulated to modify a service's execution parameters through tools such as the service controller, sc.exe, PowerShell, or Reg. Access to Registry keys is controlled through access control lists and user permissions. (Citation: Registry Key Security)(Citation: malware hides service)

Adversaries may attach filters to a network socket to monitor then activate backdoors used for persistence or command and control. With elevated permissions, adversaries can use features such as the library to open sockets and install filters to allow or disallow certain types of data to come through the socket. The filter may apply to all traffic passing through the specified network interface (or every interface if not specified). When the network interface receives a packet matching the filter criteria, additional actions can be triggered on the host, such as activation of a reverse shell.

Adversaries may encode data with a standard data encoding system to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a standard data encoding system that adheres to existing protocol specifications. Common data encoding schemes include ASCII, Unicode, hexadecimal, Base64, and MIME.(Citation: Wikipedia Binary to text Encoding)(Citation: Wikipedia Character Encoding) Some data encoding systems may also result in data compression, such as gzip.

Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges. Adversaries may do this to execute commands as other users or spawn processes with higher privileges.

Adversaries may use Valid Accounts to remotely control machines using Virtual Network Computing (VNC). VNC is a platform independent desktop sharing system that uses the RFB (“remote framebuffer”) protocol to enable users to remotely control another computer’s display by relaying the screen, mouse, and keyboard inputs over the network.(Citation: The Remote Framebuffer Protocol)