Definitions Part II

Collection of variables of same name, same data type, same size BUT different subscript numbers/element an array to store names of ten students of a class may be defined in acomputer language like : DIM names [10] .
ARU Audio Respond Unit. Used as output device. gives out output in voice form.
ASCII American Standard Code for Information Interchange. It is a character set used as a standard to store and retrieve, send and recieve data and information on different media. Assembler Converts programs written into assembly language into machine language. It does it line by line. Assembly language A low level language, bit easy as compared to machine language but quite difficult as compared to high level languages. Needs an assembler to translate it's code into machine code. Asynchronous transmission A type of transmission that sends data using flow control rather than a clock to synchronize data between the source and destination.
AT Advance Technology. Class of IBM PC compatibles having processors 80286 and higher.
ATM Automated Teller Machine. Used at banks as cash dispencing machine. It is always On-line to the bank database.
Audio compression A technique for reducing the size of sound files on disk. Depending on the compression scheme , it may reduce sound quality. Automatic Backup A backup utility that uses a software timer to trigger backups at set times, or network utility that backs up local hard drives to a server without users having to do anything.
AVI Audio Video Interlaced. Microsoft's standard file format for digital video.
Back end The server component of a client-server system. It provides services to the front-end (the client component).
Background printing The process of printing behind the scenes while you work in another file or application. Windows comes with a print spooler called Print Manager, which enables you to use background printing with almost any Windows application.
Backup A method used to have another copy of important data at a safe place on a safe medium.
Bandwidth In network communications, the amount of data that can be sent across wire in a given time. Each communication that passes along the wire decreases the amount of available bandwidth.
Bar chart A data chart designed to compare quantities at evenly spaced time intervals. Bar charts emphasize each interval's data point, the individual numeric value represented by each bar's height.
Barcode Series of thin and thick lines / light and dark bars which uniquely identifies an item.
Batch file A file containg a series of DOS commands, each on its own line, that executes automatically when you type the name of the file at DOS prompt and press enter key. Batch files enable you to speed up
repetitive tasks.
Batch printing The ability to send several files to the printer in a single operation.
Batch processing It is the process in which inputs are collected for certain period of time and are then processed at a specific time. eg. A payroll processing system.
Baud It is the rate at which data is transferred along a communication line. Normally one bit per second.
Baud rate The per-second rate of state transitions (i.e. from 1 to 0 and vice verse) of a signal. Baud rate of
modems define the speed at which they make state transitions. Because state transitions can represent
more than a single bit each, this rate is different from Bits Per Second (BPS) rate.
BBS Bulletin Board Service. A home-brewed version of an on-line service such as Compu Serve or America On Line, where people dial up with their modems and leave messages or files for others to read or download. Anyone with a modem and the right software can turn a PC into a BBS, and almost all small BBSs charge little (or nothing) for access.
BCD Binary Coded Decimal. An obselete character code. Benchmark A speed test performed under controlled conditions. Binary search A very fast search algorithm/technique. It uses sorted field to search for a match.
BIOS Basic Input Output System. It is a computer program written in machine language and "Hard Burned" into CMOS. Needed at startup of a computer.
Bit Abbreviation of Binary digit. a bit can have a value either zero (0) or one (1). smallest measurement unit of data in a computer. 8 bits makes 1 byte
Bit-mapped graphics Images stored as grid of dots. Paint programs, scanners, and fax modems save data as bitmaps.

How To Deal With Computer Virus?

Virus Effect your system in different ways. Most of the time slow internet browsing due to virus effect; infects virus attack on Network Services; (svchost.exe) you suffer Slow Internet Browsing or if you suffer slow Computer Speed. Some time virus attack on your system resources and utilize the full processor speed. In this condition you should restart your computer and then speed will be normal but after some time virus again make your system speed slow. In these conditions, if you don’t have any antivirus installed in your computer then do the following steps.

What should you do?
When you have Virus in Your Computer?
When your computer infected with Virus?

Follow the Following Steps

1. Call IT support If you have an IT support department at your disposal, notify them immediately and follow their instructions.

2. Disconnect your computer from the Internet Depending on what type of Trojan horse or virus you have, intruders may have access to your personal information and may even be using your computer to attack other computers. You can stop this activity by turning off your Internet connection. The best way to accomplish this is to physically disconnect your cable or phone line, but you can also simply “disable” your network connection.

3. Back up your important files At this point it is a good idea to take the time to back up your files. If possible, compile all of your photos, documents, Internet favorites, etc., and burn them onto a CD or DVD or save them to some other external storage device. It is vital to note that these files cannot be trusted, since they are still potentially infected. (Actually, it’s good practice to back up your files on a regular basis so that if they do get infected, you might have an uninfected set you can restore.)

4. Scan your machine
Since your computer (including its operating system) may be infected with a malicious program, it is safest to scan the machine from a live CD (or “rescue” CD) rather than a previously installed antivirus program. Many antivirus products provide this functionality. Another alternative is to use a web-based virus removal service, which some antivirus software vendors offer (try searching on “online virus scan”). Or you could just try Microsoft’s web-based PC Protection Scan. The next best action is to install an antivirus program from an uncontaminated source such as a CD-ROM. If you don’t have one, there are many to choose from, but all of them should provide the tools you need.

After you install the software, complete a scan of your machine. The initial scan will hopefully identify the malicious program(s). Ideally, the antivirus program will even offer to remove the malicious files from your computer; follow the advice or instructions you are given. If the antivirus software successfully locates and removes the malicious files, be sure to follow the precautionary steps in

Step 7 to prevent another infection. In the unfortunate event that the antivirus software cannot locate or remove the malicious program, you will have to follow Steps 5 and 6.

5. Reinstall your operating system
If the previous step failed to clean your computer, the most effective option is to wipe or format the hard drive and reinstall the operating system. Although this corrective action will also result in the loss of all your programs and files, it is the only way to ensure your computer is free from backdoors and intruder modifications.
Many computer vendors also offer a rescue partition or disc(s) that will do a factory restore of the system. Check your computer’s user manual to find out whether one of these is provided and how to run it.
Before conducting the reinstall, make a note of all your programs and settings so that you can return your computer to its original condition.
It is vital that you also reinstall your antivirus software and apply any patches that may be available. Consult “Before You Connect a New Computer to the Internet” for further assistance.

6. Restore your files If you made a backup in Step 3, you can now restore your files. Before placing the files back in directories on your computer, you should scan them with your antivirus software to check them for known viruses. 7. Protect your computer
To prevent future infections, you should take the following precautions:
• Do not open unsolicited attachments in email messages.

Do not follow unsolicited links.
• Maintain updated antivirus software.
• Use an Internet firewall.
• Secure your web browser.

• Keep your system patched.
To ensure that you are doing everything

Free Hard Disk Data Recovery

Restoration is an easy to use and straight forward tool to undelete files that were removed from the recycle bin or directly deleted from within Windows. Upon start, you can scan for all files that may be recovered and also limit the results by entering a search term or extension. In addition, Restoration also provides an option to wipe the found files beyond simple recovery. And as such it is not only a data-recovery tool but also a security cleanup application. You can use it after deletion of confidential documents, embarrassing files and so on. The program is very small and standalone, it does not require installation and can also run from a Floppy disk. Restoration works with FAT and NTFS as well as digital cameras cards.

Types of Computer Virus

Adware: *A form of spyware that collects information about the user in order to display
advertisements in the Web browser based on the information it collects from the user's
browsing patterns.
Software that is given to the user with advertisements already embedded in the

Malware: *Short for malicious software, software designed specifically to damage or
disrupt a system, such as a virus or a Trojan horse.
Script Kiddie: *A person, normally someone who is not technologically sophisticated,
who randomly seeks out a specific weakness over the Internet in order to gain root access
to a system without really understanding what it is s/he is exploiting because the
weakness was discovered by someone else. A script kiddie is not looking to target specific
information or a specific company but rather uses knowledge of a vulnerability to scan
the entire Internet for a victim that possesses that vulnerability.
Spyware: *Any software that covertly gathers user information through the user's
Internet connection without his or her knowledge, usually for advertising purposes.
Spyware applications are typically bundled as a hidden component of freeware or
shareware programs that can be downloaded from the Internet; however, it should be
noted that the majority of shareware and freeware applications do not come with
spyware. Once installed, the spyware monitors user activity on the Internet and transmits
that information in the background to someone else. Spyware can also gather
information about e-mail addresses and even passwords and credit card numbers.
Spyware is similar to a Trojan horse in that users unwittingly install the product when
they install something else. A common way to become a victim of spyware is to download
certain peer-to-peer file swapping products that are available today.
Aside from the questions of ethics and privacy, spyware steals from the user by using the
computer's memory resources and also by eating bandwidth as it sends information back
to the spyware's home base via the user's Internet connection. Because spyware is using
memory and system resources, the applications running in the background can lead to
system crashes or general system instability.
Because spyware exists as independent executable programs, they have the ability to
monitor keystrokes, scan files on the hard drive, snoop other applications, such as chat
programs or word processors, install other spyware programs, read cookies, change the
default home page on the Web browser, consistently relaying this information back to the
spyware author who will either use it for advertising/marketing purposes or sell the
information to another party.
Licensing agreements that accompany software downloads sometimes warn the user that
a spyware program will be installed along with the requested software, but the licensing
agreements may not always be read completely because the notice of a spyware
installation is often couched in obtuse, hard-to-read legal disclaimers.
Trojan: *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.
The term comes from a story in Homer's Iliad, in which the Greeks give a giant wooden
horse to their foes, the Trojans, ostensibly as a peace offering. But after the Trojans drag
the horse inside their city walls, Greek soldiers sneak out of the horse's hollow belly and
open the city gates, allowing their compatriots to pour in and capture Troy.
Virus: *A program or piece of code that is loaded onto your computer without your
knowledge and runs against your wishes. Viruses can also replicate themselves. All
computer viruses are man made. A simple virus that can make a copy of itself over and
over again is relatively easy to produce. Even such a simple virus is dangerous because it
will quickly use all available memory and bring the system to a halt. An even more
dangerous type of virus is one capable of transmitting itself across networks and
bypassing security systems.
Since 1987, when a virus infected ARPANET, a large network used by the Defense
Department and many universities, many antivirus programs have become available.
These programs periodically check your computer system for the best-known types of
Some people distinguish between general viruses and worms. A worm is a special type of
virus that can replicate itself and use memory, but cannot attach itself to other programs.
Worm: *A program or algorithm that replicates itself over a computer network and
usually performs malicious actions, such as using up the computer's resources and
possibly shutting the system down.
* Definitions provided by Webopedia

Virus Resources

McAfee :
Symantec Norton:
Trend Micro:
Free software
AVG Anti-Virus - Free
F-Prot - Free for home users
Free online Virus scan
BitDefender -
Computer Associates -
HouseCall -
McAffe -
Panda ActiveScan -
RAV Antivirus -
Free online Trojan scan
TrojanScan -
Free online Security scan
Symanted Security Check -
Test my Firewall -
More Security Resources
Forum of Incident Response and Security Teams:
SANS Institute:

Information Systems Security Training

Virus damage estimated at $55 billion in 2003. “SINGAPORE - Trend Micro Inc, the world's third-largest anti-virus software maker, said Friday that computer virus attacks cost global businesses an estimated $55 billion in damages in 2003, a sum that would rise this year. Companies lost roughly $20 billion to $30 billion in 2002 from the virus attacks, up from about $13 billion in 2001, according to various industry estimates.” This was the story across thousands of news agencies desk January 2004. Out of $55 billion, how much did it cost your company? How much did it cost someone you know? The purpose of this class is to inform the attendee about how malicious code works, how they spread, and how to protect yourself from infection. The most well know viruses will
be covered in the first part of the presentations along with the most recent. The attendee will also learn several methods (while used in combination) that will minimize both risk of infection and potential damages caused by them. The attendee should have a basic knowledge of computers and be familiar with the Microsoft Windows platform (Win9x, WinNT, Win2k, WinXP, Windows 2003 server).