utility programs

ASSIGNMENT 18

Utility programs

These are standard programs that run under control of the operating system just like your applications programs. They are called utilities because they perform general types of functions that have little relationship to the content of the data. Utility programs eliminate the need for programmers to write new programs when all they want to do is copy, print, or sort a data file.

Utility programs categories
-Disk Cleanup (cleanmgr.exe) is a computer maintenance utility included in Microsoft windows designed to free up disk space on a computer's hard drive. The utility first searches and analyzes the hard drive for files that are no longer of any use, and then removes the unnecessary files. There are a number of different file categories that Disk Cleanup targets when performing the initial disk analysis:
 Compression of old files
 Temporary Internet files
 Temporary Windows file
 Downloaded Program files
 Recycle Bin
 Removal of unused applications or optional Windows components
 Setup Log files
 Offline files
The above list, however, is not exhaustive. For instance, 'Temporary Remote Desktop files' and 'Temporary Sync Files' may appear only under certain computer configurations, differences such as Windows Operating System and use of additional programs such as Remote Desktop. The option of removal hibernation data may not be ideal for some users as this may remove the hibernate option.

-Disk checkers is a command on computers running DOS, OS/2 and Microsoft Windows operating systems that displays the file system integrity status of hard disks and floppy disk and can fix logical file system errors. It is similar to the fsck command in Unix. On computers running NT-based versions of Windows, CHKDSK can also check the disk surface for physical errors or bad sectors, a task previously done by SCANDISK. This version of CHKDSK can also handle some physical errors and recover data that is still readable.

-File managers is a computer program that provides a user interface to work with file systems. The most common operations used are create, open, edit, view, print, play, rename, move, copy, delete, attributes, properties, search/find, and permissions. Files are typically displayed in a hierarchy. Some file managers contain features inspired by web browsers, including forward and back navigational buttons.

-Backup utility refers to making copies of data so that these additional copies may be used to restore the original after a data loss event. The verb is back up in two words, whereas the noun is backup (often used like an adjective in compound nouns).
Backups are useful primarily for two purposes. The first is to restore a state following a disaster (called disaster recovery). The second is to restore small numbers of files after they have been accidentally deleted or corrupted. Data loss is also very common. 66% of internet users have suffered from serious data loss.

-Defragmentation is a process that reduces the amount of fragmentation in file systems. It does this by physically organizing the contents of the disk to store the pieces of each file close together and contiguously. It also attempts to create larger regions of free space using compactionto impede the return of fragmentation. Some defragmenters also try to keep smaller files within a single directory together, as they are often accessed in sequence.

-Data compression is the process of encoding information using fewer bits (or other information-bearing units) than an unencoded representation would use, through use of specific encoding schemes.
Another related concept to compression is that of Data deduplication. In computing, data deduplication is a specialized data compression technique for eliminating coarse-grained redundant data, typically to improve storage utilization.

-Virus protection is used to prevent, detect, and remove malware, including computer viruses, worms, and trojan horses. Such programs may also prevent and remove adware, spyware, and other forms of malware.
A variety of strategies are typically employed. Signature-based detection involves searching for known malicious patterns in executable code. However, it is possible for a user to be infected with new malware for which no signature exists yet. To counter such so-called zero-day threats, heuristics can be used.

-Data recovery is the process of salvaging data from damaged, failed, corrupted, or inaccessible secondary storage media when it cannot be accessed normally. Often the data are being salvaged from storage media such as hard disk drives, storage tapes, CDs, DVDs, RAID, and other electronics. Recovery may be required due to physical damage to the storage device or logical damage to the file system that prevents it from being mounted by the host operating system.

-Diagnosis utility recovers data from the message store. The utility tool checks the synchronization status of each subscription that the user is associated with and checks if it needs recovery. If it does, the tool recovers and writes the recovery status in an output file. You can run this utility before deleting or resetting a device or user ID to collect data that can help you diagnose client synchronization problems.

INTRODUCTION COMPUTER THREAT

ASSINGMENT 17

INTRODUCTION COMPUTER THREAT
The computer is a great tool to store important information. In certain cases, the information is very vital that losing it will harm the computer system.

Computer threats can come from many ways either from human or natural disasters. For example, when someone is stealing your account information from a trusted bank, this threat is considered as a human threat. However, when your computer is soaked in heavy rain, then that is a natural disaster threat.

MALICIOUS CODE
Malicious code is also known as a rogue program. It is a threat to computing assets by causing undesired effects in the programmer’s part. The effect is caused by an agent, with the intention to cause damage.

The agent for malicious code is the writer of the code, or any person who causes its distribution. There are various kinds of malicious code. They include virus, Trojan horse, logic door, trapdoor and backdoor, worm and many others.
a) VIRUS
• a program that can pass on the malicious code to other programs by modifying them
• attaches itself to the program, usually files with .doc, .xls and .exe extensions
• destroys or co-exists with the program
• can overtake the entire computing system and spread to other systems

b) TROJAN HORSE
• a program which can perform useful and unexpected action
• must be installed by users or intruders before it can affect the system’s assets
• an example of a Trojan horse is the login script that requests for users’ login ID and password
• the information is then used for malicious purposes

c) LOGIC BOMB
• logic bomb is a malicious code that goes off when a specific condition occurs.
• an example of a logic bomb is the time bomb
• it goes off and causes threats at a specified time or date

e) TRAPDOOR OR BACKDOOR
• a feature in a program that allows someone to access the program with special privileges

f) WORM
• a program that copies and spreads itself through a network

Primary Differences Between Worms And viruses

Worm Virus
Operates through the network Spreads through any medium
Spreads copies of itself as a standalone program Spreads copies of itself as a program that attaches to other
programs
HACKER
Hacking is a source of threat to security in computer. It is defined as unauthorised access to the computer system by a hacker. Hackers are persons who learn about the computer system in detail. They write program referred to as hacks. Hackers may use a modem or cable to hack the targeted computers.

NATURAL AND ENVIRONMENTAL THREATS
Computers are also threatened by natural or environmental disaster. Be it at home, stores, offices and also automobiles.Examples of natural and environmental disasters:
 Flood
 Fire
 Earthquakes, storms and tornados
 Excessive Heat
 Inadequate Power Supply

THEFT
Two types of computer theft:
1) Computer is used to steal money, goods, information and resources.
2) Stealing of computer, especially notebook and PDAs.

Three approaches to prevent theft:
1) prevent access by using locks, smart-card or password
2) prevent portability by restricting the hardware from being moved
3) detect and guard all exits and record any hardware transported

computer security

ASSIGNMENT 16

COMPUTER SECURITY

DEFINITION OF COMPUTER SECURITY
Computer security means protecting our computer systems and the information they contain against unwanted access, damage, destruction or modification.

We need to protect our computer from any intruders such as hackers, crackers and script kiddie.

We do not want strangers to read our e-mail, use our computer to
attack other systems, send forged e-mail from our computer, or examine personal information stored on our computer such as financial statements.


TYPES OF COMPUTER SECURITY
Three types of computer security are:
a) hardware security
b) software security/data security
c) network security

a) HARDWARE SECURITY
Hardware security refers to security measures used to protect the hardware specifically the computer and its related documents.

The examples of security measures used to protect the hardware include PC-locks, keyboard-locks, smart cards and biometric devices.

b) SOFTWARE AND DATA SECURITY
Software and data security refers to the security measures used to protect the software and the loss of data files.

Examples of security measures used to protect the software are activation code and serial number.

c) NETWORK SECURITY
The transfer of data through network has become a common practice and the need to implement network security has become significant.

PERSONAL COMPUTER SECURITY CHECKLIST
In order to make sure our computers are secured, here are the computer
security checklist to follow.
 Do not eat, drink or smoke near the computer
 Do not place the computer near open windows or doors
 Do not subject the computer to extreme temperatures
 Clean the equipment regularly
 Place a cable lock on the computer
 Use a surge protector
 Store disks properly in a locked container
 Maintain backup copies of all files
 Stores copies of critical files off sites
 Scan a floppy disk before you open it
 Do not open any unknown email received