Unit 4:Network Security And System Software✔️ Flashcards
What are the goals of penetration testing - “pen” testing
-identify targest of potential attacks
-identify entry points
-attempt to break in
-report back findings
What does anti-malware software do?
Protects network /system agaist malware(trojans,virus,worms) Detects the malware reports it to anti-malware company -virus is confirmend and signature is created of the virus - added to database - users urged to update software
What is encryption?
A way of secuing data so it cannot be read without an ecryption key
Change plain text to cipher text
Encyrption of transmitted data?
Website use HTTPS(Secure Hypertext transfer protocol) encrypt the conection to the server
What is the purpose of encrypting drives ?
Prevents hackers from understanding the conent of the hard drive if removed or installed on a different computer.
What is a firewall
-seperates a trusted network from an untrusted network(normally the internet)
-packets entering are checked
-run on dedicated hardware or as software
-built into wifi routers
What is the job of the firewall?
Checks packets to see where they are coming from and going to for malcious content like viruse,trojans
Firewall features?
-Prevents attackers gaining access to computers on network
-block packets from a certain ip address
-block inappropiate or malcious software
Issues with firewall?
-software firewalls slow down a computer
-dedicated hardware firewalls are expensive
What are user access levels?
Controls which part of the network users can access and edit such as:internet,emails and software
What is password policy?
Organisation and computer systems will often have password policy which determine what features the password must include.
Eg,numbers,8 letters ling
What is Physical security?
Where hardware,software and network are protecte by physical methods.
Examples:CCTV,alarms,locks,fenses,guards,id cards
What is packet inspection?
When a firewall will look at data inside each packet to see if it contains mallicious content
What is malware?
Malware are executable programs that run on a compuer.
Example:virus
What do viruses do?
-replecate their code in other programs
-infect other computers
-delet,corrupt and modify files
-need to be opened by human(not self replicating)
What do worms do?
-normally do not cause damage to computer
-might slow down network and computers
-replicate without human intervention
What do trojans do?
Usually program,game or craked file user wants but contains code which causes damage,takes control or provides access to computer
What is ransomware?
-holds computer hostage-locks user out - encrypts access
-nearlly impossible to get data without backup
-once ransom paid access is restored
What is social ingineering?
Ability to obtain confidential information by appearing professional and secure/safe
What is shoulder surfing?
Ability to obtain information by observing someone as the type it it.
Eg:standing behind them,ussing cctv cameras
What is phishing?
-type of social engineering
-emails,text,phone calls send to user seem legit and try to get your password,usernames,credit card details
What is a denial of service attack(Dos)
-attacker sends many requests to server (known as a flood)
-sever can not respond fast enough so slow down or goes ofline
What is a distributed denial of sevice attack (DDoS) ?
Many computers are used to send requests and flood and server
What is a Man-In-the-middle attack (MITM) ?
When a hacker is able to intercept communications between the user and server.
Can then eavesdrop to find passwords and personal info.
Easy to perform on unecrypted wifi
What is a brute fore attack?
Hacker will try every combination of the assword until correct password is found
What is an SQL injection?
Using web forms to add SQL instructions to cause data loss or the revealing of personal information
Function of an Operating system?
-user interface
-memory management and multitasking
-Periphreal managment and drivers
-user managment
-file managment
Examples of operating systems?
Windows,apple ios ,linux
What is system software?
System software is the software that provides a platform for other software to work.
What do operating sysetms do?
Manage computer hardware and resources used by software.
Manage:user interface …. ext
What are user interfaces?
Provides a method for users to interact with a computer - example is graphical user interface(GUI)
Deskto interfaces?
-Windows
-menus
-icon
-pointers
Types of user interface?
-menu-driven interface
-command line inter face (CLI)
-graphical user interface (GUI)
Pros of command line interface?
-requires little proccessing - can save money on graphics cards
-faster than using a mouse
-requires less hdd space
-less ram needed
What is command line interface (CLI)
Text commands entered into interface
Where are menu-driven interfaces used ?
Menu-driven interface often used by devices that have a dedicated function eg ATM machine or MP3 player
What is multi-tasking?
Where an operating system manages many tasks at the same time.
Eg web browser open while listening to music and messaging friends
-OS decides which process will next run on the cpu and for how long
What are interrupts?
-Interrupts are signals sent to the cpu by external devices to indicate an event that needs immediate attention.
-cpu suspens current activities to execute appropriate instructions
What are hardware interrupts?
Generated by hardware devices eg printer out of painter
What are software interupts?
Generated by programs eg 0 divided by 0 will generate an error message
What is peripheral managment?
-OS must manage inputs and send out outputs to devices
-example of peripherals: mice,keyboard,webcam,microphone
What are devie drivers?
Device driver is a program that controls periphreal devices such as printer,mice and displays
-each device communicates via its own driver
Hard disk?What peripheral are they?
-hard disk - storage peripheral-stores computers data,can be encrypted
File managment and the operating system?
-Manages where the disks files are written
-keeps track of where they are so they can be retrieved
-make sures the files are not overwritten
Features avaiable with file managment?
-naming files
-moving file
-saving files
-deleting files
User managment?
Operating system is resonsible for password and user logins.
-stores passwords in a database
What are Access rights?
-if a computer used by more the 1 person they should only see their files
-users and system admins have different levels of access rights
-some user may only be allowed to read files not edit them
What is utility software?
Utility programs perfrom extra functions and housekeeping jobs to help keep the computer functioning-often packaged as part of OS - example: antivirus software
Utility software example?
-encryption software
-defragementation software
-data compression
-house keeping tools - disk clean up ext
What is encryprtion software?
Software used to encrypt sensetive data-changes plain text to cipher text - can not be understood without key
How to know if web browser is encrypted?
There is usually a padlock for sites that are using HTTPS
What does HTTPS stand for?
Hypertext transfer protocol secure
Organisations that use email encryption?
-companies sharing internal files
-accuntant disscussing financial information
-schools sharing info about students
What are encryption software utilities used for?
-encrypt storage on Hard drive - cant be understood if stolen
-encrypt files on portable usb/removable storage
-encrypt communication with websites
What is data decompression software?
Utilities like WInZip allow users to compress files/folders
-reduce amount of space used on hard drive
-reduces amount of data sent when sending files
-more data can be stored on backup media
What does defragmenting the hard disk do?
Reorganises the files - they are stored together-reuces load times
Pros of defragmenting?
-read times are faster
-free space in one location - new files dont need to be fragmented
What does it mean if a file is ‘fragmented’
If you save a large file it might not fit on the disk in consequtive memory locations so it is split up.
Issues with ‘fragmentin’ files?
-drive head needs to moe to more locations to read file
-slowe to access files/programs
