Cybersecurity - PLTW EoC Exam

Malware

Software spread by people through websites, email, and messages.

Viruses

Infect your computer and cause problems.

Worm

Unlike a virus, a worm does not need a human to spread; it replicates on its own to infect other computers.

Backdoor

Malicious software that gets past normally restricted access.

Spyware

Software that secretly collects information about you; sits on websites or other services such as emails.

Trojan Horse

Malicious program disguised as legitimate software; users may download it accidentally thinking it was actual software.

.bat Batch File

Opens a Batch file script.

.vbs VBScript (Virtual Basic Script)

Opens VBScript.

.hta HTML

Opens a program.

\

Used to find any word or file name.

datemodified\today and datemodified[date]

Used to find files modified on that specific date.

kind=

Used to find a file in a specific location.

kind=folder

Used to find a file in any folder.

\SEC kind=folder

Used to find SEC in any file name in any folder.

kind=\

Used to find any kind of file.

datemodified\

Used to find a file from any date.

Using NOT

You can exclude things in your search.

CIA Triad

Confidentiality, Integrity, Availability.

Confidentiality in the CIA Triad

Government secrets, access codes to critical systems, financial info like bank account and credit card numbers.

Integrity in the CIA Triad

Air traffic control data, hospital data such as prescription doses and surgery schedules.

Availability in the CIA Triad

Movie times, shopping sites, search engines and results.

Disconnect

An add-on that prevents extra websites not related to the original website from popping up.

Passive Analysis

Searching through a website’s details without affecting their systems.

AWS

Secure cloud service that is an expansion of different services and serves many functions.

Cloud9

A way to access data without hurting your computer.

Whois

Shows when a domain was created and by whom; shows info about a URL.

sudo yum install

Install code system.

Nslookup

Allows user to find domain names, URLs, and IP addresses.

Traceroute

Shows the path a network, server, and domain goes.

-d

Omits domain name translation.

Netstat

Converts IP addresses to domain names.

-n

Displays numeric IP addresses.

Botnet

Software that replicates and infects many computers, turning them into “zombies” remotely controlled by attackers.

Keylogger

Software/hardware that tracks what keys are pressed to gain info from the user.

Man in the Middle

Human-based attack where a user intercepts communication between a computer and the internet.

Ransomware

Software that locks a computer, forcing the user to pay to unlock it.

Rootkit

Software with elevated privileges to control a computer or gain restricted accounts and data.

Programming Error

Bugs/problems in a program that allow attackers to access the computer.

Ping Flood

Attacker overwhelms a user with packets.

Ping of Death

Sends malicious ping to a computer.

Smurf Attack

Sends packets to exploit broadcast networks.

Mailbomb

Attempting to overflow a mailbox.

Teardrop

Sending fragmented packets to one computer.

MAC Addresses

Permanent identifier of a network device; used to know where to send data.

Hexadecimal

Base-16 number system (0-9 & A-F).

NIC

Network Interface Card; a physical component on a computer or device that provides connectivity to a network.

IEEE

Institute of Electrical and Electronic Engineers; known for developing standards in the computer and electronics industries.

TCP Handshake

A 3-way communication method using SYN, SYN-ACK, and ACK to establish a connection between hosts.

ls

Lists the contents of a directory.

-R

Shows the entire directory structure recursively.

cd

Changes directory.

cd [filename]

Changes to a subdirectory.

cd ..

Changes to the parent directory.

.

Indicates the current directory.

pwd

Prints the working directory.

cat

Displays the contents of a file.

mkdir

Creates a directory.

mv

Moves a file/directory to a new name or location.

mv [source] [destination]

Moves files.

touch

Creates a file or changes its timestamp.

cp

Copies a file/directory to a new name or location.

cp [source] [destination]

Copies files.

rm

Deletes a file.

rmdir

Deletes an empty directory.

file

Shows a file’s type as determined by the operating system.

gpg

Encrypts/decrypts a file.

-c

Creates an encrypted version of a file.

-d

Decrypts an encrypted file.

ps

Shows running system processes.

-ef

Shows everyone's processes in a formatted output.

--sort=uid

Groups all user processes together.

more

Displays file content like cat, but lets you scroll.

bg/fg

Sends process to background or brings it to foreground.

grep

Searches for strings in a file or command output.

-e

Searches for multiple separate strings.

su

Changes your user ID to root (admin).

kill

Terminates a process.

-9 or -KILL

Forcefully kills a process.

-w

Filename where packets will be saved.

-n

Records IP addresses instead of hostnames.

Cipher

An algorithm used for encryption or decryption.

Cryptography

The science/art of delivering a message securely.

Plain text

The original message before encryption.

Cipher text

The encrypted version of the message.

Substitution Cipher

Replaces each letter with a different character or symbol.

Encryption Key

A string that determines the output of an encryption algorithm.

Private Key Encryption

Sender and receiver share the same key.

Symmetric Key Encryption

Same key used for encryption and decryption.

Public Key Encryption

Uses large prime numbers, private and public keys.

TPM

Trusted Platform Module; provides secure encryption for a drive.

Disk

The physical drives in a computer.

Volume

The accessible storage area on a disk.

Partitions

A section of a volume formatted for storage.

Hash Functions

Converts data of any size into a fixed size.

Steganography

Hides messages within other data.

Least Significant Bit

The rightmost bit in a byte.

Alternative Data Stream

Attaches data to a file without changing its content or size.

Digital Watermarking

Embeds small information without impairing the file.

Message Digests

The hash value generated by a hash function.