1.3.3c, 1.3.3d and 1.3.3e networks Flashcards

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1
Q

what is malware

A
  • malicious software written to cause damage/harm to computer or devices on network
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2
Q

give examples of malware

A
  • viruses
  • worms
  • trojan horse
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3
Q

give some typical actions of malware

A
  • delete / modify files
  • scareware
  • locking / corrupting files
  • opening backdoors (holes in someone’s security which can be used for future attacks)
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4
Q

what is a virus and how can they be spread

A
  • malicious software designed to cause harm to network by attaching themselves to programs or file on computer or server
  • often spread through attachments to emails but also spread through files, programs or games downloaded from web page
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5
Q

what can a virus do

A
  • delete / corrupt data
  • change system files so they become corrupted
  • can fill hard drive so computer runs slower / becomes unresponsive
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6
Q

what is a worm

A
  • replicates itself in order to spread to other computers which uses up a computer’s resource’s and causes other programs to run slowly
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7
Q

how does a worm spread

A
  • replicates itself to spread and can also spread across network, consuming network bandwidth
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8
Q

how are worms different to viruses

A
  • don’t need to be hosted in a program. they can create back doors so a hacker can take over infected computer
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9
Q

what is a trojan horse

A
  • looks like legitimate software and creates backdoors + slows computer down
  • program that can be downloaded and installed on computer that appears harmless but is actually malicious
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10
Q

what is spyware

A
  • malware that covertly / secretly aims to collect information about a user’s computer activities by transmitting data from their device
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11
Q

list how spyware can be used in different way to harvest all sorts of sensitive and personal data from a device.

A
  • cookies
  • keystrokes
  • credit card numbers
  • passwords
  • downloads
  • visited web pages
  • email addresses
  • internet surfing habits
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12
Q

what is a keylogger

A
  • type of spyware
  • secretly collects / monitors activity of computer system and send data elsewhere without victim knowing
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13
Q

what is ransomware

A
  • software that encrypts all files and then demands victim for payment to decrypt them
  • no pay = key deleted
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14
Q

what is adware

A
  • software that causes popups or windows that won’t close
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15
Q

what are rootkits

A
  • alter permissions giving hackers administrator level access to devices
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16
Q

what is a botnet

A
  • collection of computers infected with malware and controlled by hackers
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17
Q

what is a man-in-the-middle attack

A
  • intercepting a devices connection to internet achieved by luring users into fake Wi-Fi hotspot
  • operators of fake Wi-Fi hotspot then packet sniff to gain personal info that could be used in further attacks
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18
Q

what is a DOS attack

A
  • attackers prevent user from accessing a network or website by flooding servers with traffic
  • this makes the network extremely slow (takes up bandwidth) and so they cant respond to legitimate client requests (inaccessible to intended users on network)
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19
Q

what do DOS attacks tend to exploit

A
  • exploit limitation of TCP/IP stack
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20
Q

what servers do DOS attacks tend to target

A
  • web servers of high-profile organisations
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21
Q

what is a DDOS attack

A
  • multiple systems orchestrate a synchronised DOS attack against a single target
  • uses a larger number of compromised machines that have been infected with malware (botnets formed from these “zombie” computers)
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22
Q

how can you prevent from DOS and DDOS

A
  • protection services available which can intercept and analyse potential threats (resource requested and visitors IP address)
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23
Q

there are protection services available to prevent against DOS and DDOS attacks which can intercept and analyse potential threats such as visitors IP addresses. what type of IP address is inspected for and why

A
  • proxy server IP addresses as these IP addresses mask the real identity of the real device(s) so are likely malicious packets
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24
Q

what is an SQL injection

A
  • attack uses SQL code on website to query a database attached to website to try and retrieve personal sensitive info
  • they use certain characters to form query that is executed by the server which could return all sensitive info to attack data-driven applications
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25
Q

SQL injection attacks are designed to do what

A
  • exploit vulnerabilities in poorly designed / coded databases
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26
Q

how can you prevent against SQL injection

A
  • input sanitation (ensures only permitted characters used. input sanitation code will remove any other characters from input)
  • identified exploits must be patched to reduce impact of attack on an organisation
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27
Q

what is a brute force attack

A
  • hacker attempts to crack password by systematically trying different combinations of characters until correct one is found
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28
Q

what is packet sniffing

A
  • interception of data packets being routed on a network using packet analysers that read and display contents of each packet
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29
Q

what is social engineering

A
  • gaining sensitive info or illegal access to networks by manipulation techniques to exploit human error
  • tend to use fear to put people off guard as they will be more likely to comply to instructions given to them
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30
Q

what is the weakest point of any computer system

A
  • people that use it
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31
Q

how can people as a weak point be mitigated

A
  • through user training + education programs
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32
Q

what is shoulder surfing

A

finding out sensitive personal info by means of watching people enter them (look over shoulder)

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33
Q

what is phishing

A
  • online fraud technique used by cybercriminals to trick users into giving personal info
  • sending emails purporting to be from reputable / legitimate companies to induce people to divulge personal information
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34
Q

what do phishing attacks normally involve

A
  • often ask user to verify account by clicking link which takes user to spoof version of website where details are captured by hackers and can be used to commit offences
35
Q

what are the impacts of phishing

A
  • identity / data theft
  • acquisition of victim’s usernames and passwords or credit card detail etc.
36
Q

what is pretexting / blagging

A
  • persuading victim to divulge info often by fake scenario
  • criminal will usually pretend to be from official organisation
37
Q

what is baiting

A
  • leaving a malware infected portable storage device around hoping a legitimate user will insert it into computer system and thus malware is installed which can harm computer
38
Q

what is tailgating / piggybacking

A
  • physical security breach whereby an unauthorised person follows an authorised individual to enter a secured premise
39
Q

what is a hoax virus

A
  • an infected email such as a chain email that is forwarded on by people therefore sending and spreading virus to more computers
40
Q

what is pharming

A
  • malicious code installed on server / computer that redirects user to a malicious / spoof / fraudulent website without their knowledge by modifying DNS entries
41
Q

how can one prevent pharming

A
  • web filters
42
Q

what is penetration testing

A
  • testers take on role of hackers to test a system in order to identify vulnerabilities in its security that an attacker could exploit.
43
Q

what does penetration testing test and demonstrate

A
  • test for network vulnerabilities
  • assess security awareness of employees to see how likely they can be tricked by social engineering ploys

-demonstrates effectiveness of network security policies

44
Q

what is a white box tester

A

IT tech who tests with knowledge of system (can access all parts of system)

45
Q

what is a grey box tester

A

testing system / application with partial knowledge of internal structure to identify vulnerabilities

46
Q

what is a black box tester

A

testing a system with no prior knowledge of its internal workings (like a real hacker trying to exploit vulnerabilities)

47
Q

what is a hacker

A

person who attempts to gain access to a compute system with intent of damaging data or harming system

48
Q

what is a white hat hacker

A
  • ethical hackers employed by company who use their expertise to investigate a network to identify vulnerabilities and security risks
49
Q

what is a grey hat hacker

A
  • search for and identify security flaws in companies without permission
50
Q

what is a black hat hacker

A

hack for illegal purposes and with malicious intentions for financial gain or commit significant damage

51
Q

why do all networks need protection

A
  • need protection from unwanted intrusion and hacking
52
Q

what is the aim of network security

A
  • only allow authorised users access
  • prevent unauthorised access
  • minimise potential damage caused by unauthorised access
53
Q

list some methods of physical security

A
  • guards
  • alarms
  • security cameras
  • biometric authentication
  • security barriers
  • walls / fencing
  • locked cabinets
  • locks on certain areas
54
Q

what is password security

A
  • username and password
  • symbols, numbers, caps, more than 12 characters
  • 2FA
  • password reset policies
  • limited number of guesses
  • CAPTCHA
55
Q

how can updates ensure network security

A
  • patches correct errors or network vulnerabilities
  • update anti-malware and OS
56
Q

what is a proxy server

A
  • sits between device/network and internet server (remote source)
  • filters traffic
  • Provides gateway between users and internet (intermediary server)
  • no direct connection between user and remote source
57
Q

what does a proxy server do (functions)

A
  • caching: keeps copies of data downloaded (reduce bandwidth of needing to send request for same resource)
  • logging and monitoring traffic
  • security: external users unable to see or access devices inside network (only contact is to proxy)
  • privacy: can be external to network and used to fetch webpages (proxy server IP address logged and not the user’s)
58
Q

what is a firewall

A
  • software or hardware that controls and monitors (scans) incoming and outgoing network traffic, blocking ports / unintended traffic routed from outside a LAN based on predetermined security rules.

(prevents unauthorised access from outside LAN and user in LAN from accessing parts of internet)

59
Q

what are the 3 types

A
  • personal
  • departmental
  • enterprise
60
Q

what is encryption

A
  • plain text to cipher text
  • encrypts sensitive data so if intercepted, data = meaningless
  • only authorised users can access confidential info
  • follows rules of legislation (DPA)
61
Q

what are user access levels

A
  • system administrator can set a hierarchy of users in an organisation so users access data for their status
  • restricts unauthorised access
62
Q

which main attack does user access levels prevent against

A
  • insider attacks where someone who works for organisation can steal and/or share confidential info
63
Q

why are insider attacks particularly dangerous

A
  • they don’t act maliciously so harder to detect
  • insiders know weaknesses in the organisations cybersecurity
  • they know the location and nature of sensitive data so they can abuse that power
64
Q

what is MAC address filtering

A
  • block traffic from unknown device. only allows certain MAC addresses to join / send data across a network
65
Q

what is anti malware

A
  • blocks malware so it can’t affect device/system
66
Q

what are the 3 purposes of anti-malware software

A
  • detect malware being installed
  • prevent malware being installed
  • remove malware from system
67
Q

how does anti-malware protect the system

A
  • performs real time scans of incoming network traffic
  • performs scans of whole systems looking for malicious applications
  • if malware detected, software handles it by quarantining it which prevents it from running allowing user to remove it
68
Q

what must you ensure you do regularly with anti-malware software

A
  • update with latest patches
69
Q

what is a modem

A
  • transforms digital info from computer into analogue signals that can be transmitted through wires. this process can happen vice versa.

Not used to communicate over LAN

70
Q

how and why does a modem transfer these digital signals into analogue signals (vice versa)

A
  • it does this by modulating and demodulating electrical signals sent through wiring
  • does this to change signal so it can be sent through cable that uses a different technology.
71
Q

how many ports does a standalone modem have

A
  • 2 (one connection to outside world and the other is an ethernet port connecting to computer or router)
72
Q

if an organisation had a modem and a router, which one (or both integrated together) could allow them to connect to the internet

A
  • both are needed (integrated or not) to connect organisation to the internet
73
Q

what is a wireless access point

A
  • connects to a wired router, switch or hub via ethernet cable and allows Wi-Fi signal within a designated area
  • creates wireless local area network (WLAN)
74
Q

what is a network interface card / controller

A
  • allows device to connect to a network
  • allows both wired (Ethernet protocol) and wireless (Wi-Fi protocol) connections between computers on LAN or connected to large-scale network using IP
  • contains MAC address
75
Q

Fill the gaps:

An NIC is both a _______ layer and ____ ____ layer device, providing necessary circuitry for ________ layer processes and some ____ ____ layer processes to run on it

A
  • physical
  • data link
  • physical
  • data link
76
Q

what is a hub

A
  • connect multiple devices to 1 network
  • broadcasts transmissions it receives to all other connected devices and correct destination will accept data
  • can cause data traffics, slower than switches
77
Q

what type of device is a hub considered as (active/passive) and what layer does it operate on

And why?

A
  • passive device
  • operates on physical layer
  • it simply broadcasts transmissions it receives to all other connected devices
78
Q

what type of device is a switch considered as (active/passive) and what layer does it operate on

And why?

A
  • active device
  • operates on data link layer
  • it can inspect transmissions and route packets to destination keeping unnecessary traffic to a minimum
79
Q

for data transfer, what is faster: switches or hubs

A
  • switches
80
Q

what is a gateway

A
  • device used to allow transmission of data between dissimilar networks like networks that use different protocols.
  • provides compatibility between the different protocols used in the 2 different networks
  • combines variety of operations like malware inspection + spam filtering.
81
Q

what can an Internet of Things (IoT) gateway be used for

A

An Internet of Things (IoT) gateway can be used to collect sensor data from connected devices and forward them to a user’s smartphone.

82
Q

what is transmission media

A
  • way in which packets transmitted across a network
  • cables to connect devices or wirelessly via radio waves
83
Q

what are the 3 network cables

A
  • Unshielded Twisted Pair (UTP): (ethernet cable)
  • Fibre Optic
  • Coaxial Cables