what is computer virus ?

Engr. Md. Alihyder BhuiyanNetwork and Security Administrator

Information Technology DivisionMercantile Bank Limited

Head Office, Dhaka, Bangladesh.Ph: +88 01611 001 606

• Viruses

• Worms

• Trojans

• Malware

• Spyware

• Grayware and Adware

Introducing to:

Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation.

A virus might corrupt or delete data on your computer, use your e-mail program or LAN to spread itself to other computers, or even erase everything on your hard disk

What is Computer Viruses ?

Symptoms of a computer virus

• The computer runs slower than usual.• The computer stops responding, or it locks up frequently.• The computer crashes, and then it restarts every few minutes.• The computer restarts on its own. Additionally, the computer does not

run as usual.• Applications on the computer do not work correctly.• Disks or disk-drives are inaccessible.• You cannot print items correctly.• You see unusual error messages.• You see distorted menus and dialog boxes.

Symptoms of a computer virus (cont.)

• There is a double extension on an attachment that you recently opened, such as a .jpg, .vbs, .gif, or .exe. extension.

• An antivirus program is disabled for no reason. Additionally, the antivirus program cannot be restarted.

• An antivirus program cannot be installed on the computer, or the antivirus program will not run.

• New icons appear on the desktop that you did not put there, or the icons are not associated with any recently installed programs.

• Strange sounds or music plays from the speakers unexpectedly.• A program disappears from the computer even though you did not

intentionally remove the program.

How do Viruses Spread?

• Viruses are often spread by over LAN or any Removal Disk or attachments in e-mail messages or instant messaging messages. That is why it is essential that you never open e-mail attachments unless you know who it's from and you are expecting it.

• Viruses can be disguised as attachments of funny images, greeting cards, or audio and video files.

• Viruses also spread through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.

What is Worms ?

• A computer worm is a program which copies itself across a network.

• A computer worm differs from a computer virus in that a computer worm can run itself.

• A virus needs a host program to run, and the virus code runs as part of the host program.

• A computer worm can spread without a host program, although some modern computer worms also use files to hide inside.

Windows Security Alert Message

Message

What is Trojan Horse ?

• A Trojan horse is not a virus. It is a program that you run because you think it will serve a useful purpose such as a game or provides entertainment.

• For example, you might download what you think is a new game; but when you run it, it deletes files on your hard drive .

• Or the third time you start the game, the program E-mails your saved passwords to another person who writes this program.

• it will scour your hard drive for any personal and financial information such as your social security, account, and PIN numbers. Once it has collected your info, it is sent to a thief’s database.

Symptoms of worms and Trojan horse viruses in e-mail messages

• The infected file may make copies of itself. This behavior may use up all the free space on the hard disk.

• A copy of the infected file may be sent to all the addresses in an e-mail address list.

• The computer virus may reformat the hard disk. This behavior will delete files and programs.

• The computer virus may install hidden programs, such as pirated software. This pirated software may then be distributed and sold from the computer.

Symptoms of worms and Trojan horse viruses in e-mail messages (Cont.)

• The computer virus may reduce security. This could enable intruders to remotely access the computer or the network.

• You receive an e-mail message that has a strange attachment. When you open the attachment, dialog boxes appear, or a sudden degradation in system performance occurs.

• Someone tells you that they have recently received e-mail messages from you that contained attached files that you did not send. The files that are attached to the e-mail messages have extensions such as .exe, .bat, .scr, and .vbs extensions.

What is Malware ?

• Malware is a generic term for bad software and portmanteau of "malicious software". The term refers to any computer program that harms the computer running it

• Malware generally includes Spyware, Trojans, Adware, rootkits, dialers, Key loggers, denial of service attacks, botnets, Crimeware, Badware, viruses worms and any other types of unwanted or potentially unwanted software. However, in the strictest sense, the term "Malware" expresses its purpose rather than any particular characteristic.

This is how to prevent infection by Malware ?

• Do not click on pop-up advertisements.• Do not open e-mails from unfamiliar or questionable sources.• Do not respond to online requests for personal information, such

as Social Security number, passwords, usernames or any other identifiers that could be used for fraudulent activities.

• Download only those software programs that come from reputable sources.

• Install a good anti-virus product, and make sure you are running the latest updates at all times.

What is Spyware ?

• Spyware are programs, cookies or registry entries that track your activity & send that data off to someone who collects this data for their own purposes. Usually, those people are marketing companies trying to collect information to help them sell better.

Spyware (cont.)

Spyware (cont.)

• Spyware is often associated with software that displays advertisements (called adware) or software that tracks personal or sensitive information.

Spyware (cont.)

• Spyware basically collects personal information of the user and can even change settings on the user’s computer.

Warning Message of Spyware

What is Grayware ?

• Grayware are programs that are neither spyware or a virus.

• If an application is classified as annoying or behaves in annoying or undesirable fashion, yet isn’t considered to be as dangerous, serious, or troublesome as malware, it is called Grayware or Greyware. Typically, Grayware can encompass all of the following :

– Adware– access tools– dialers– joke programs– remote access tools– Spyware

Some Symptoms that may be the result of ordinary Windows functions

A computer virus infection may cause the following problems

• There is frequent modem activity. If you have an external modem, you may notice the lights blinking frequently when the modem is not being used. You may be unknowingly supplying pirated software

• Windows does not start because certain important system files are missing. Additionally, you receive an error message that lists the missing files

• You receive out-of-memory error messages even though the computer has sufficient RAM.

Windows does not start even though you have not made any system changes or even though you have not installed or removed any programs.

Some Symptoms that may be the result of ordinary Windows functions Continuation

• The computer sometimes starts as expected. However, at other times, the computer stops responding before the desktop icons and the taskbar appear.

• The computer runs very slowly. Additionally, the computer takes longer than expected to start.

• New programs are installed incorrectly.• Windows spontaneously restarts unexpectedly.• Programs that used to run stop responding frequently. Even if you

remove and reinstall the programs, the issue continues to occur.

Some Symptoms that may be the result of ordinary Windows functions Continuation

• A disk utility such as Scandisk reports multiple serious disk errors.• A partition disappears.• The computer always stops responding when you try to use Microsoft

Office products.• You cannot start Windows Task Manager.• Antivirus software indicates that a computer virus is present.

Is This Solutions ?

Centralize Solutions

VPN

Internet

Antivirus Parents Server

Antivirus Child Server

Router

PC




PCPCPC

PCPCPC

PCPCPC

PCPCPC

PCPC

Switch

SwitchSwitch

Switch

Router

Router

Router

Router

Switch

VPN Router

A) Antivirus Parent Server will be updated directly from Internet. In scheduled interval the child server/PC’s attached with the parent server will be updated automatically.B) Antivirus Child Server will be updated from Parent server. The child server will updated all other’s PC’s attached with it.

Use Any good Anti Virus

eScan Version 10

eScan Management Console

Confidential Property

Presenting eScan Version 10

Intelligent & Faster

User Friendly

Multi-level Protection

Parental Control

Highly Competitive Pricing Structure

eConceal Firewall


Exciting New Features

• Proactive Security

• New User Friendly GUI

• Parental Control

• End Point Security

• Faster On Demand Scans

• Full Fledged Firewall

• Registry Monitoring

• Suspicious Application Detection

• Enhanced Comprehensive Reports

• Block Games/Chat/Media Player/P2P Applications


Password Protection with read only access


eScan Version 10 - GUI


eScan Protection Center


Protection Center – File AntiVirus


Features include:

• New File Monitor (intelligent and Faster)

• MWL Scanning

• Real-Time AV Scanning

• Spyware, Adware, Keylogger, & Rootkit Blocker

• Suspicious Application Detection

• Registry Monitoring

File Anti-Virus : Features


Protection Center – Mail AntiVirus


Features include:

• Real-Time eMail Scan

• Password Protected settings

Mail Anti-Virus : Features


Protection Center – Web AntiVirus


Web Anti-Virus : Features

Features include:

• Web/FTP/CHAT Scanning

• Block websites with restricted words

• Block web content (Multi-Media & Applications)

• Block web applets, Cookies, Scripts

• Privacy Protection / Browser Security

• Block Pop-Ups

• Time Restriction for Web access


Protection Center – End Point Security


Features include:

• USB / Firewire Control

• Application Control

End Point Security : Features


Protection Center – Privacy Control


Features include:

• Spyware & Keylogger Blocker

• Privacy Protection / Browser Security

• Block Pop-Ups

Privacy Control : Features


Protection Center – Anti Spam


Protection Center – Firewall


Scan


Custom Scan Options


Custom Scan Options (Cont.)


Features include:

• Heuristic Scanning

• On Demand Scanning with Cache Technology

• Backup before Disinfection

Scan : Features


Compressed Updates


Useful Tools

How to Quick Scan Your System ?

Scan your PC by MWAV


eScan 10 Product Comparison


eScan 10 Product Comparison Contd..


Thank YouInformation Technology Division

what is computer virus ?

Documents