Textbook Notes (369,205)
Canada (162,462)
CIS 1000 (58)
Zoe Zhu (26)
Chapter 9

Chapter 9.docx

6 Pages

Computing and Information Science
Course Code
CIS 1000
Zoe Zhu

This preview shows pages 1 and half of page 2. Sign up to view the full 6 pages of the document.
Chapter 9: Securing Your System Keeping Your Data Safe - Cybercrimes are criminal acts conducted by cybercriminals through the use of computers - Cybercriminals are individuals who use computers, networks and the internet to perpetrate crime - Computer users need to protect themselves from becoming victims of cybercriminals - The Internet Crime Complaint Centre (IC3) processed more than 275,000 complaints related to internet crime in 2008 - The majority of complaints (more than 58%) were related to three key areas: Internet auction fraud, non-delivery of merchandise or failure to pay - Much of the credit card fraud is perpetrated when credit card numbers are stolen by phishing (tricking people into revealing information) or by virus programs that gather credit card data - Non-fraud-related complaints pertained to issues such as computer intrusions, unsolicited e-mail, and child pornography - Creating and disseminating computer viruses is one of the most widespread types of cybercrimes Computer Threats: Viruses - A computer virus is a computer program that attaches itself to another computer program (known as the host program) and attempts to spread to other computers when files are exchanged - Viruses normally attempt to hide within the code of a host program to avoid detection - Viruses, by definition, have a method to spread themselves - Virus creation and deployment is a form of cybercrime - A computer virus’s main purpose is to replicate itself and copy its code into as many other files as possible - Although virus replication can slow down networks, it is not usually the main threat - The majority of viruses have secondary objectives or side effects, ranging from displaying annoying messages on the computer screen to destroying files or the contents of entire hard drives - If the computer is exposed to a file infected with a virus, the virus will try to copy itself and infect a file on your computer - Shared disks or flash drives are common sources of virus infection, as is e-mail - Downloading or running a file attached to an e-mail is how a computer becomes effected - Types of viruses:  Boot-Sector Viruses  A boot-sector virus replicates itself into a hard drive’s master boot record  The master boot record is a program that executes whenever a computer boots up, ensuring that the virus will be loaded into memory immediately, before anti-viruses can load  Logic Bombs and Time Bombs  A logic bomb is a virus that is triggered when certain logical conditions are met  A time bomb is a virus that is triggered by the passage of time or on a certain date  Worms  A worm is slightly different from a virus in that a worm attempts to travel between systems through network connections to spread an infection  Script and Macro Viruses  A script is a series of commands (a mini-program) that is executed without your knowledge  A macro virus is a virus that attaches itself to a document  E-mail viruses use the address book in the victim’s email system to distribute the virus  Encryption Viruses  When encryption viruses infect your computer, they run a program that searches for common types of data files and compresses them using a complex encryption key that renders your files unusable - Types of virus classifications:  A polymorphic virus changes its own code to avoid detection  A multipartite virus is designed to infect multiple file types in an effort to fool the antivirus software that is looking for it  Stealth viruses temporarily erase their code from the files where they reside and then hide in the active memory of the computer Computer Safeguard: Antivirus Software - Antivirus software is software specifically designed to detect viruses and protect computers and files from harm - Although antivirus software is designed to detect suspicious activity on your computer at all times, you should run an active virus can on your entire system at least once a week - Most antivirus software looks for virus signatures in files – a virus signature are portions of the virus code that are unique to that particular computer virus - Antivirus software scans files when they’re opened or executed - If it detects a virus signature or suspicious activity, it stops the execution of the file and notifies you it has detected a virus; usually it gives you the choice of deleting or repairing the infected file and places the virus in a secure area – this is called quarantining - Through inoculation, the antivirus software records key attributes about files on your computer and keeps these statistics in a safe place on your hard drive - Antivirus software catches known viruses effectively; thus your computer can still be attacked by a virus that your antivirus software does not recognize – to minimize this risk, keeping your antivirus software up to date is key - Other ways to protect your system are:  Keeping your computer’s antivirus and operating system (OS) software up to date  Loading security patches as soon as they are available  Enabling automatic updates for both the OS and all other software loaded on your computer - To keep your instant messaging sessions safe, follow these precautions: 1. Allow contact only from users on your buddy or friends list 2. Never automatically accept transfers of data 3. Avoid using instant messaging programs on public computers - Malicious websites can be set up to attack your computer by downloading harmful software onto your computer. According to research conducted by Google, an attack known as a drive-by download, is common and affects almost 1 in 1000 web pages - Although many people decide to receive updates automatically, there are several options you can choose from in Windows. The following options are noteworthy:  Option 1: Install updates automatically  Option 2: Download updates but let me choose whether to install them  Option 3: Check for updates but let me choose whether to download and install them  Option 4: Give me recommended updates  Option 5: Microsoft update Computer Threats: Hackers - A hacker is defined as anyone who unlawfully breaks into a computer system, whether it's an individual computer or a network - A hacker who breaks into systems just for the challenge of it may refer to himself/herself as a white- hat hacker – they tout themselves as experts who are performing a needed service for society by helping companies realize the vulnerabilities that exist in their systems - White hat hackers call hackers who use their knowledge to destroy information or for illegal gain black hat hackers - Amateur hackers are referred to as script kiddies – script kiddies don’t create the programs they use to hack into computer systems; instead, they use tools created by skilled hackers - If you perform financial transactions online, credit card and bank account information can reside on your hard drive and may be detectable by a hacker - Even if this data is not stored on your computer, a hacker might be able to capture it when you’re online by using a packet sniffer - Data travels through the internet in small pieces, each called a packet - A packet sniffer is a program that looks at each packet as it travels on the internet – not just those that are addressed to a particular computer, but all packets - Some packet sniffers are configured to capture all the packets into memory, whereas others capture only those packets that contain specific content - Once a hacker has access to credit card information, he/she can either use it to purchase items illegally or sell the information to someone who will - If hackers can gather enough information in conjunction with your credit card info, they may be able to commit identity theft - Identify theft is characterized by someone using personal information about you to assume your identity for the purpose of defrauding others - A Trojan horse is a program that appears to be something useful or desirable, but something malicious runs in the background without your knowledge - Often, the malicious activity perpetrated by a Trojan horse program is the installation of a backdoor program that allows hackers to take almost complete control of your computer without your knowledge - A computer that a hacker controls in this manner is referred to as a zombie - In a denial-of-service (DoS) attack, legitimate users are denied access to a computer system because a hacker is repeatedly making requests of that computer system through a computer he/she has taken over as a zombie - Launching a DoS attack on a computer system from a single computer is easy to trace - Most savvy hackers use a distributed denial-of-service (DDoS) attack, which launches DoS attacks from more than one zombie at the same time - A botnet is a large group of software programs (called robots or bots) that runs autonomously on zombie computers - Logical ports are virtual communications gateways or paths that allow a computer to organize requests for information from other networks or computers Restricting Access to Your Digital Assets - A firewall is a program or hardware device designed to protect computers from hackers - A firewall spe
More Less
Unlock Document

Only pages 1 and half of page 2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.