Protecting against Serious Threats against Computer Systems and Networks - Assignment Example

Figure 1: Question 5 How the task was done: The drawing was first done in AutoCAD. Drawing tools: lines, circles, rectangles, hatches, text and dimensions were used in combination to produce the drawing. Modify commands also came in quite handy in editing the draw commands appropriately. To paste the drawing from AutoCAD into Ms Word, the system-wide copy command is used to copy the drawing into the clipboard, and then pasted into Word. However, using the paste command directly would paste it as a link to the original AutoCAD drawing, therefore Paste Special command is used. Using Paste Special command, the drawing can be pasted into the Word document as a Picture (Enhanced Metafile) The original scale as done in AutoCAD is kept in place only as long as the drawing is pasted without tampering with the aspect ratio of the image. QUESTION 1 COMPUTER THREATS AND HOW THEY REMOVED We are no longer safe in this world we live in. There is always one person out there waiting to attack us in anyway possible. Even our computer systems are no longer safe. Vital information can be stolen in an instant from our government, which could be sold over the black market to terrorist organizations who could potentially use that information against us and possibly destroy the back bone of this fine country. We must stop these ruthless acts against our computers systems and say no more! The CompTIA organization has created a helpful certification to help IT professionals get in the game to help protect our computer systems. They created Security+ to help protect against serious threats against computer systems and networks. “Theft and destruction of intellectual property takes place despite the presence of firewalls, encryption and corporate edicts. Neither technologies nor policies alone offer effective information security. The IT industry must have a well-trained work force to effectively combat hackers and decrease. In the past decade, computer and networking technology has seen enormous growth. This growth however, has not come without a price. With the advent of the "Information Highway", as its coined, a new methodology in crime has been created. Electronic crime has been responsible for some of the most financially devastating victimizations in society. In the recent past, society has seen malicious editing of the Justice Department web page (1), unauthorized access into classified government computer files, phone card and credit card fraud, and electronic embezzlement. All these crimes are committed in the name of "free speech." These new breed of criminals claim that information should not be suppressed or protected and that the crimes they commit are really not crimes at all. What they choose to deny is that the nature of their actions are slowly consuming the fabric of our country's moral and ethical trust in the information age. Federal law enforcement agencies, as well as commercial computer companies, have been scrambling around in an attempt to "educate" the public on how to prevent computer crime from happening to them. They inform us whenever there is an attack, provide us with mostly ineffective anti-virus software, and we Scanners and disinfectors, the most popular classes of anti-virus software, rely on a great deal of a prior knowledge about the viral code. Scanners search for "signature strings" or use algorithmic detection methods to identify known viruses. Disinfectors rely on substantial information regarding the size of a virus and the type of modifications to restore the infected file's contents. Viruses are currently designed to attack single platforms. A platform is defined as the combination of hardware and the most prevalent operating system for that hardware. As an example, a virus can be referred to as an IBM-PC virus, referring to the hardware, or a DOS virus, referring to the operating system. "Clones" of systems are also included with the original platform. "Social engineering" is the final method of gaining unauthorized system access. People have been known to call a system operator, pretending to be some authority figure, and demand that a password be changed to allow them access. One could also say that using personal data to guess a user's password is social engineering. \ A file virus attaches itself to a file, which is usually an executable application (e.g. a DOS program or a word processing program). Generally, file viruses don't infect data files. But, data files can contain embedded executable code such as macros, which can be exploited by computer virus or Trojan horse authors. Recent versions of Microsoft Word and Excel are particularly vulnerable to this type of threat. Text files such as batch files, postscript files, and source codes that contain commands which can be compiled or interpreted by another program are potential targets for malware (malicious software). Boot sector viruses modify the program which is in the first sector (boot sector) of every DOS-formatted disk. In general, a boot sector infector executes its own code (that normally infects the boot sector or partition sector of the hard disk), then continues the PC boot up (start-up) process. In most cases, all write-enabled floppy disks which are used in that PC from then on will become infected. Multipartite viruses have some of the features of both the above types of viruses. When an infected file is executed, it typically infects the hard disk boot sector or partition sector, and therefore infects subsequent floppy disks which are used or formatted in the target system. Computer viruses: The threat today and the expected future. Many of these types of viruses related to DOS programs were commonly found several years ago when DOS programs were mainly used in the computers, but are rarely found and reported now a days. Typically macro viruses infect global settings files such as Microsoft Word, Excel templates so that subsequently edited documents are infected with the infective macros. Macro viruses will be discussed in more details at next section. Stealth viruses are the viruses that go to some length to hide their presence from programs that might notice. Polymorphic viruses are the viruses that cannot be detected by searching for a simple, single sequence of bytes in a possibly infected file, because they change with each replication. Companion viruses are the viruses that spread through a file that runs instead of the file the user intended to run, and then runs the original file. For example, the file MYAPP.EXE may be 'infected' by creating a file called MYAPP.COM. Because of the way DOS works, when the user types MYAPP at the C> prompt, MYAPP.COM is run instead of MYAPP.EXE. MYAPP.COM runs its infective routine, and then quietly executes MYAPP.EXE. N.B. this is not the only type of companion (or 'spawning') virus. A more modern way to achieve this is to create files that have the same name, but are placed on another branch in the file tree. If the file is cleverly placed, failure to write the full path will result in executing the false file. Armored viruses are the viruses which are specifically written to make it difficult for an anti-virus researcher to find out how they work and what the QUESTION 4 The line graph above represents trigonometric functions. First the values of x were tabulated and the range was 0 ≤ x ≤ 10 for intervals of 0.1 in a MS Excel book. In cells adjacent to the value of x, appropriate formulas were inserted. For f1(x), the formula was as follows: =5*(SIN (2*A3))/(2*(A3+1)) For f2(x), the formula was as follows: =COS (2*A3)*EXP(-A3/4) For f3(x), the formula was as follows: =TANH (A3/2)*SIN (2*A3) The value A3 was the cell containing the value of x referenced in the formula. This was the formula for the first cell in which the value of x at that instant was 0. To obtain subsequent values, the cells were auto-filled to give the values for the graph. Line f1(x) represents the function f1(x) given. Line f2(x) represents the function f2(x) given. Line f3(x) represents the function f3(x) given. Read More