The three technologies that describe the primary cloud service models as defined by the National Institute of Standards and Technology (NIST) are Platform as a Service (PaaS), Software as a Service (SaaS), and Infrastructure as a Service (IaaS). These service models are based on the type of computing capability that is provided by the cloud provider to the cloud consumer over a network. According to NIST, these service models have the following definitions:

• Platform as a Service (PaaS): The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.
• Software as a Service (SaaS): The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser (e.g., web-based email), or a program interface. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
• Infrastructure as a Service (IaaS): The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications; and possibly limited control of select networking components (e.g., host firewalls).

References: The NIST Definition of Cloud ComputingNIST Cloud Computing Program

If you consume application infrastructure (middleware) capabilities by a third-party provider, then the cloud service model that you are using in this scenario is PaaS, which stands for Platform as a Service. PaaS is a cloud service model that provides customers with a platform to develop, run, and manage applications without having to deal with the underlying infrastructure or software. PaaS typically includes middleware capabilities such as databases, web servers, development tools, integration services, etc., that customers can use to build and deploy their applications faster and easier. MaaS, DaaS, and SaaS are not cloud service models that match this scenario, as they stand for different types of services. MaaS stands for Monitoring as a Service, which is a service that provides customers with tools to monitor and manage their cloud resources and performance. DaaS stands for Desktop as a Service, which is a service that provides customers with virtual desktops that they can access from any device or location. SaaS stands for Software as a Service, which is a service that provides customers with software applications that they can use over the internet without installing or maintaining them. References: [PaaS], [MaaS], [DaaS], [SaaS].

Two statements that describe a website categorized as a domain generated algorithm (DGA) are: The website is used to hide a command-and-control server and the domain was created by a program. A domain generated algorithm (DGA) is a technique used by cyber attackers to generate new domain names and IP addresses for malware’s command and control servers. Executed in a manner that seems random, it makes it nearly impossible for threat hunters to detect and contain the attack. A command-and-control server is a server that communicates with malware installed on infected machines and sends commands or updates to them. A program is a piece of software that performs a specific task or function. A domain generated algorithm is implemented by a program that runs on the attacker’s machine or the malware itself, and produces a large number of domain names based on some logic, such as date, time, seed, dictionary, etc. References: Domain generation algorithmAmong cyber-attack techniques, what is a DGA?