Systems Software and Security

Systems Software and Security

1. Network Threats

   • Phishing
     • What is Phishing?
       • An email that scams the target into giving away personal details or money
     • Who does it target?
       • Over 800,000 phishing email are sent every day. Over 80 000 get through, and 8000 people are conned out of their money .
       • Phishers often target vulnerable people who are mpre likely to fall for the scam; the elderly, disabled or simply less computer-able.
     • How can you prevent it?
       • There are many ways to spot a phishing email: they often have bad grammar and spelling, they will not adress you directly,and there could be a sense of urgency.
       • For a phishing scam to work, there will be link you must click. if you hover your mouse over this link, and it seems dogy, don't click it. duh,.
   • Denial of Service (DoS)
     • What is DoS?
       • A DoS attack is an attack in which the service/site is overloadeed with so many requests that it cannot function and shuts down.
     • Who Does it Target?
       • A DoS attack targets a big company or site, in order for them to stop working
       • However, this is not always an intentional attack; sometimes there are simply just to many requests and the site can crash.
     • How Can it Be Prevented?
       • There is not really much you can do about these attacks except ensure that your site is working as fast and fluently as possible
   • Malware
     • Types of malware
       • Virus
         • This is a type of malware that infests a computer system then multi[lies, and fills up all available storage or corrupts files until the computer crashes
         • Prevention is better than cure; set up a firewall before a virus can get to you in the first place.
       • Trojan Horse
         • A destructive program that masquerades as a benign application. Unlike viruses, Trojan horses do not replicate themselves but they can be just as destructive. One of the most insidious types of Trojan horse is a program that claims to rid your computer of viruses but instead introduces viruses onto your computer.
       • Worm
         • A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it. Unlike a computer virus, it does not need to attach itself to an existing program.
       • Spyware
         • This is a malware that collects data of the victim whtihout their knowledge.
           • An example of this would be a key logger; a program which records teh victims key strokes. when reveiwed, the attacker can then pick out sensitive data such as passwords.

2. Identifying and Preventing Vulnerabilities

   • Hackers
     • Black hat hackers
       • These hackers are malicious hackers, who act unethically and their sole purpose is to take down the site they are attacking
     • Grey hat hackers
       • These hackers are ethical, however, they do not gain the companys permission before hacking. when they uncover a flaw, they will report it to the company instead of exploitign it. still, this is breaking the law and they can be punished rather than rewarded for their efforts. An example of Grey-Hat hackers are the group anonymous.
     • White hat hackers
       • These hackers are employed by companies to try to hack into the own compny's system. they do this to find and fix flaws in the site's security, so tht black-hat hackers annot exploit the flaw.
   • Acceptable Use Policies
     • An acceptable use policy is a set of rules that users of a network have to agree to before using said network. this hightens security and helps to stop hackers.
     • an acceptable use policy might include: Don't use another user's password. Don't tell others your password. Don’t use the internet inappropriatly. Don’t use email or internet to gamble.
   • Firewalls
     • A firewall is a software program or piece of hardware that helps screen out hackers, viruses, and worms that try to reach your computer over the Internet.
   • Penetration Testing
     • Pen’ testing is the practice of deliberately trying to find security holes in your own systems
   • Black- and white-box testing
     • In black box testing, testers are given no more information than any potential hacker may have In white box testing, testers are given as much information as an ‘insider’ may have, in order to determine how much damage a rogue employee could do to a system
   • Interior Security
     • User access levels
       • Depending how authoratitive you are, you have access to different amounts of data. for examlpe, in school, students have access to their own files and workfiles only, but teachers can reach all students files. teachers however, cannot see toher teachers files, and so on.
     • Passwords
       • You must try to have a differnet password for each account you have. also, try to use a combination of letters, numbers, other characters.

3. Operating System Software

   • What is an operating system?
     • the low-level software that supports a computer's basic functions, such as scheduling tasks and controlling peripherals.
       • it manages:Memory, Multitasking, Peripherals, Files, User Access Aights
   • User Interface
     • The User Interface translates binary into a format we can understand, and can communicate with the programme
     • Types of User Interface
       • GUI : Graphical user interface. this is such things as WIMP (Windows, icons, menus and pointers) it allows the user to communicate with the programme with images rather than text-based navigation.
       • Menu-driven interface uses a menu in which the user can choose between options to navigate to. eg a cash machine or an ipod.
       • CLI: Command Line Interface in which the user types a command on a line, the computer sends back a response etc. it takes up much less space in RAM because it uses no graphics.
       • Vioce activated interfaces respond to a pre-programmable voice command.
       • Real time interface is when a sensor detects an input and notifies the cpu.
   • Memory Management and Multitasking
     • To run a program, the computer must copy the program from storage into main memory . This means that teh computer must manage whats going on.
     • You may use your computer to do several tasks at the same time with different software: homework, playing music, messaging friends...
   • Peripheral Management and Devices Drivers
     • A device driver is a program that controls a peripheral device such as a printer, VDU, CD-ROM drive etc. Each device communicates with the OS via its own driver Many device drivers are built into the operating system but if you buy a brand new type of device, it will be supplied with a driver, which you will need to install
     • Peripheral Manaegment manages input and output devices. Peripheral Management gets input, sends output, copies files from disk to memory, and copies data files back to secondary storage.

4. Utility Software

   • Encryption Software
     • Encryption software is used to transform text so that it cannot be read without knowing the key to decode it
       • Messaging services use it.
   • Defragmentation Software
     • When files are stored on a disk, they are just stored wherever there is room. this means that the same file could be split up (fragmented) and stored all across the disk. when you next need to access the file, it takes longer to load becuse it is fragmented. defragmentation ssoftware re-organises the disk so that all 'like' files are stored together, thus making the loading process faster.
   • Data Compression Software
     • Reduces bandwidth usage and data consumption to download and send a compressed file
     • Can enable file sizes to fit with strict email attachment or ISP limits and increases the amount of data that can be stored or archived on disk
   • Back up
     • Full Back up
       • Complete backup of everything which can be restored independently of any other backup
       • Takes greater time and disk space to create the backup
     • Incremental Back up
       • Records only the changes made since the last backup
       • A entire chain of backups is required to fully restore files