Cyber is now mainstream and part of everyday lives. Since April, more than 200,000 incidents
have been reported to the Internet Crime Complaint Center, a major pipeline was shut down in
the U.S., and the world’s largest meat processing company was a victim of ransomware.
According to the Army Criminal Investigation Command’s Major Cybercrime Unit, the best way
to protect against cybercrime is with knowledge and understanding of what cybercrime entails.
The below commonly used cyber terms is a follow-up to Cyber Terminology 101 and should be
used as a quick reference guide to intermediate well-known cyber terms.
Commonly Used Terms
Authentication Factor: Data that is used to identify an individual for access to an information
system. Authentication factors can be something you know (usernames, passwords, secret
questions), something you have (USB token, smart card, PKI certificate), something you are
(fingerprint, DNA, retina pattern), something you do (annotating text from an image, clicking
only images of storefronts), or somewhere you are (GPS location).
Backdoor: Refers to any method which allows an authorized or unauthorized user to bypass
some or all security measures to gain access to a computer system, network, or software
application. Not all backdoors are nefarious—they can be used to assist users who become
locked out of their system.
Beacon: A type of malware that systematically calls out to a specified IP address or URL from a
victimized system. A waiting threat agent can answer this beacon, establishing a connection that
provides partial or even full remote access to the victimized system.
Black Hat: A hacker that breaks into a network or device without consent to conduct malicious
activities that can be used to harm the owner/users.
Ciphertext: The unreadable, unintelligible group of alpha-numeric characters produced from a
cipher (an algorithm for performing encryption or decryption) or the input to an inverse cipher.
Clickjacking: An attack that tricks victims into clicking on a disguised link, potentially causing
the victim to reveal confidential information or allowing others access to the victim’s system.
Client: A host that is seeking to use the resources of a server.
Client/Server Network: In this network, individual workstations send requests to a central
server, and the server provides all resources.
Computer Network Exploitation (CNE): Consists of techniques and processes that use
computers or computer networks to gather data on targeted systems and networks.
Cracking: When an attacker generates a set of values that represent possible legitimate
authentication factors and then tests those values against the authentication system to see which
Cross-site Scripting (XSS): Occurs when an attacker sends a script that is executed by a victim
system’s web browser or in another browser window accessing a different site.
Cryptocurrency: Or simply crypto, is any digital currency that uses an online ledger and
cryptography to secure transactions.
Cryptography: The discipline that embodies the principles, means and methods for the
transformation of data to hide their semantic content, prevent their unauthorized use, or prevent
their undetected modification.
Dark Web: Is a subset of the deep web. Its content is not indexed and consists of overlaying
networks that use the public internet but require unique software, configuration, or authorization
to access; designed to hide the identity of the user. Commonly contains anonymous journalism
and marketplaces for illegal goods and services, and is regularly used by threat actors.
Decryption: The process of transforming ciphertext into plain text.
Deepfake: An audio or video clip that has been edited and manipulated to seem real or (make
two lines believable.
Deep Web: Online content that is not indexed by traditional search engines. The content is
available to the general public but is harder to find unless you have the exact URL. Legitimate
uses of the deep web include online banking, web mail, cloud storage, and legal documents.
Denial of Service (DoS): Is an attack that inhibits a computer resource from communicating on
a network, preventing it from being available to fulfill its purpose either temporarily or
Directory: Is a centralized listing of resources such as users, groups, files and applications.
Directories are also known as folders.
Distributed Denial of Service (DDoS): Is a DoS attack that is sourced/distributed from many
different host systems. In other words, it is an attack that involves using many computers to flood
a single target simultaneously, causing a denial-of-service condition. The acronym D/DoS is a
common method for referring to both DoS and DDoS attacks.
Encryption: The conversion of plain text to ciphertext through the use of a cryptographic
algorithm. Encryption is commonly used to ensure the confidentiality and integrity of electronic
communications and is a direct application of cryptography.
Host: Any device, such as a computer, that connects to a network.
IPv4: Or IP version 4, is a 32-bit numeric address written as four sets of numbers, called octets,
separated by periods (e.g., 220.127.116.11).
IPv6: Or IP version 6, is a new method for IP addressing being implemented on newer
computers and networking equipment that provides a larger address space than the IPv4. It is
written as eight groups of hexadecimal digits separated by colons (e.g.,
Metadata: Structured information that describes, explains, locates, or otherwise makes it easier
to retrieve, use, or manage an information resource. Or more simply, metadata is data about data.
Ransomware: A form of malware that either deliberately prevents the victim from accessing
computer files—holding data hostage until a ransom is paid—or threatens to release the victim’s
data unless a ransom is paid.
Rootkit: A set of programs placed by an intruder in the system root (the directory where
operating systems files are stored) to manipulate the system and make it easier to hide his or her
Script: A list of commands that are executed by a program.
Server: A piece of hardware or software that provides services to other devices or programs in a
network. In other words, a host that receives requests to use its resources.
Structured Query Language (SQL) Injection: An attack in which unauthorized SQL
commands (or simply database commands) are used to trick a server into processing data input
as a regular database query. SQL injections allow hackers to exploit the security vulnerabilities
of the software that runs a website.
Surface Web: Contains content for the general public that is indexed by traditional search
engines and readily available by use of any internet browser. Examples include websites for
news, social networking, and even the U.S. Army’s website.
Threat: The potential source of an adverse event.
Threat Agent: Or threat actor, is a specific person or event that executes unauthorized actions
against a system.
Web Crawler: Also known as a robot; spider; or simply crawler, is a program that can be used
to automatically browse a site and follow and save all available links. Search engines use
crawlers to browse the internet and build an index of available sites to provide its users efficient
White Hat: A hacker that breaches a network to gain sensitive information with the owner’s
consent; usually employed to test infrastructure vulnerabilities.
Cybercrime Prevention Flyers (CPFs) are produced as part of the CID Cyber Lookout program to
promote internet safety for the collective Army family and to provide recommendations to
strengthen your cyber security posture and prevent cybercrime before it occurs. This CPF and all
past CPFs are available at https://www.cid.army.mil/mcu-advisories.html.