Viruses are malicious software that duplicates itself and spread thought the networks. The common way from getting viruses are by the internet. There are also different ways to obtain. From infected removable media (pen drives, external hard disk, flash drive, micro cards, floppy disc, etc.)
Online Threats
Nowadays, there are far more threats out there than plain viruses. You have probably come across the term spyware as well, however, authors of malicious codes and dangerous websites are very innovative, and new kinds of threats emerge quite often, the vast majority of which are on the Internet. Here are some of the most common:
Exploit is a malicious code that takes advantage of a flaw or vulnerability in an operating system, Internet browser, or other essential program.
Social engineering is a common term for various techniques used to trick people into giving away their personal information (passwords, bank account details, credit card numbers etc.). A typical example of social engineering is phishing – an attempt to acquire sensitive personal data by shamming a trustworthy and well-known organization. Usually, the potential victims are contacted by a bulk e-mail asking them to e.g. update their bank account details. In order to do that, they are invited to follow the link provided which then leads to a fake website of the bank.
Scam can be also considered a kind of social engineering; it includes false job offers, or ones that will abuse the workers for illegal activities, summons to withdraw a large sum of money, fraudulent lotteries and the like.
Hoax is a bulk e-mail containing dangerous, alarming or just bothering and useless information. Many of the above threats use hoax e-mail messages to spread.
They entered in your computers and started to damage or corrupt files. They even started to slow your computer as it take full capacity of your CPU (Central Processing Unit) and RAM (Random Access Memory). Computer virus is a computer program that can infect other computer programs by modifying them in such a way as to include a (possibly evolved) copy of itself". Note that a program does not have to perform outright damage (such as deleting or corrupting files) in order to be classified as a "virus" by this definition.
How do you catch a virus?
Viruses are written by malicious programmers who wish to cause problems to other computer users.
The primary source of infection these days are e-mail attachments followed by illegal software and infected files from the Internet. Also, by putting an infected floppy disk into your computer - the virus can automatically copy itself from the infected disk into your computer
If you have up to date antivirus software installed this will immediately warn you of any infection. If not, there is usually no evidence of the virus and the user is not usually aware of it until something goes wrong.
What are the symptoms and indications of a virus infection?
Many people associate destruction--file corruption, reformatted disks and the like--with viruses. Machines infected with viruses that do this kind of damage often display such damages too. This is unfortunate, as usually viruses can be detected or prevented from infecting long before they can inflict any (serious) damage, though many viruses have no "payload" at all. Note that viruses that simply reformat the hard disk shortly after infecting a machine tend to wipe themselves out faster than they spread, so don't get far.
Thus, the more successful viruses typically try to spread as much as possible before delivering their payload, if any. As these tend to be the viruses you are most likely to encounter, you should be aware that there are usually symptoms of virus infection before any (or much!) damage is done. There are various kinds of symptoms that some virus authors have written into their programs, such as messages, music and graphical displays. The main indications, however, are changes in file sizes and contents, changing of interrupt vectors, or the reassignment of other system resources. The unaccounted use of RAM or a reduction in the amount reported to be in the machine are important indicators. Examination of program code is valuable to the trained eye, but even a novice can often spot the gross differences between a valid boot sector and some viral ones. These symptoms, along with longer disk activity and strange behavior from the hardware, may instead be caused by genuine software, by harmless "joke" programs, or by hardware faults
How do viruses spread so quickly?
This is a very complex issue, and some viruses don't spread quickly at all (though talk of them often does!). Those that do spread widely are able to do so for a variety of reasons. A large target population--millions of compatible computers--helps. A large virus population helps. Vendors whose quality assurance relies on, for example, outdated scanners, help. Users who gratuitously install new software on their systems without making any attempt to test for viruses help. All of these things are factors.
There are two main types of viruses?
1. Worms
2. Trojan horse
Worm viruses are a common virus that generally duplicates itself before it spread in networks. It is a self-contained program (or set of programs), that is able to spread functional copies of itself or its segments to other Computer systems (usually via network connections).Note that unlike viruses, worms do not need to attach themselves to a host program. There are two types of worms--host computer worms and network worms.
Trojan horse is a program that does something undocumented that the programmer intended, but that some users would not approve of if they knew about it. According to some people, a virus is a particular case of a Trojan horse, namely one which is able to spread to other programs.
Protecting against Trojans
PREVENTION is the key. Don't open unanticipated file attachments from unknown sources. If you know the source, double check with them and make sure they intended to send it. Ask them exactly what it is and why you need it. If it is a game or frivolous application, delete it. Save any attachment you have a need to open and scan it with an up-to-date antivirus scanner before you launch it.
How can they be prevented?
Viruses can be prevented by taking sensible precautions, including:
- Using up to date antivirus software. E-mail attachments are now the biggest source of virus spread and many e-mail servers are now installed with anti-virus software.
- not allowing other users to use their own floppy disks on your system
- not allowing users to take the company's disks home to use on their own PC
- only downloading files from reputable Internet sites
- write-protecting disks
- avoiding software from unreliable sources
- backing up data regularly
Anti-virus software can inspect computer files and e-mail attachments for viruses and remove or quarantine any which are found.
Where viruses come from?
Viruses are codes in many forms. They are created by programmers even called hackers, that take advantage of this program to make harm to others or just for “joking”. Viruses are also created to spy and also to steal confidential information about individuals or companies, and then these information are sold on the internet.
What are hackers?
Hackers or programmers used codes to create programs. They create programs to make life become better. Nowadays I.T becomes an important thing in our society. This is the future some peoples. There are two types of hackers, the first one is name under white hackers and the other one black hackers.
The white hackers use their knowledge about codes and programming and algorithms to create programs that will improve the way of working. Businesses use computers as an important tool with all its database and programs. Also they use it as a mean of communication.eg doing video conferencing.
On the other hand there is the black hackers, the also create programs but for horrible reason. They create programs like Genvir, Virus Construction Set (VCS), Instant Virus Production Kit (IVP) to generate viruses that will spy or damage vulnerable data. These tools above are also developing by anti-virus developer or companies in lab to test their product.
Virus Construction Set
The first virus generator was VCS, written in 1990. The authors of the kit were members of the Verband Deutscher Virenliebhaber (the Association of German Virus Lovers).
VCS was a rather simple kit. All viruses that the kit can generate are 1,077 bytes and saved to VIRUS.COM on the disk. The user's only options are to specify the name of a text file with a message and to set a generation number to display that message. The VCS viruses can only infect DOS COM files. The payload of the virus is to kill AUTOEXEC.BAT and CONFIG.SYS files and display the user's message.
VCS viruses are simple but encrypted. The only remarkable feature of VCS viruses is that they can check whether the Flu Shot behavior blocker is loaded in memory and avoid infecting if it is.
Why do People Create Computer Viruses?
There are hundreds of thousands of viruses out there (if not millions) and they often designed for different objectives. Most of them fall under the following categories:
- To take control of a computer and use it for specific tasks
- To generate money
- To steal sensitive information (credit card numbers, passwords, personal details, data etc.)
- To prove a point, to prove it can be done, to prove ones skill or for revenge purposes
- To cripple a computer or network
How viruses are made?
I used to think that making viruses had something to do with programming skills. I thought writing a program that could copy itself, spread itself, hide in other programs or files, find its way around on all these different computers that surely had to be the summum of programming.
Maybe this once was true. Back in the old days, when viruses ware written in assembler, were small enough to hide in the boot sector of a floppy disk, were able to attach themselves to a file without anyone noticing (and files were quite small those days), had stealth capability, and could influence your hardware directly, bypassing the operating system.
So maybe, maybe in those days, creating viruses could be seen as an achievement, or as a sport. Now, any fool can do it. And judging by the number of viruses, a lot of them do.
Here's how.
1. Search the web for something like "Virus Construction Tool" or "Internet Worm Generator". Download it.
2. Run the program (click on its icon).
3. Fill in the form. Choose interesting names.
4. check the boxes to indicate how you want this virus / worm to spread (e-mail, irc, ...)
5. Choose your options for 'payload'
click "Done".
6. click "create virus" or "generate"
7. Save the file
8. Run it to see if it works.
How do you catch a virus?
Viruses are written by malicious programmers who wish to cause problems to other computer users.
The primary source of infection these days are e-mail attachments followed by illegal software and infected files from the Internet. Also, by putting an infected floppy disk into your computer - the virus can automatically copy itself from the infected disk into your computer.
If you have up to date antivirus software installed this will immediately warn you of any infection. If not, there is usually no evidence of the virus and the user is not usually aware of it until something goes wrong.
What are the symptoms and indications of a virus infection?
Many people associate destruction--file corruption, reformatted disks and the like--with viruses. Machines infected with viruses that do this kind of damage often display such damages too. This is unfortunate, as usually viruses can be detected or prevented from infecting long before they can inflict any (serious) damage, though many viruses have no "payload" at all. Note that viruses that simply reformat the hard disk shortly after infecting a machine tend to wipe themselves out faster than they spread, so don't get far.
Thus, the more successful viruses typically try to spread as much as possible before delivering their payload, if any. As these tend to be the viruses you are most likely to encounter, you should be aware that there are usually symptoms of virus infection before any (or much!) damage is done. There are various kinds of symptoms that some virus authors have written into their programs, such as messages, music and graphical displays. The main indications, however, are changes in file sizes and contents, changing of interrupt vectors, or the reassignment of other system resources. The unaccounted use of RAM or a reduction in the amount reported to be in the machine are important indicators. Examination of program code is valuable to the trained eye, but even a novice can often spot the gross differences between a valid boot sector and some viral ones. These symptoms, along with longer disk activity and strange behavior from the hardware, may instead be caused by genuine software, by harmless "joke" programs, or by hardware faults
How do viruses spread so quickly?
This is a very complex issue, and some viruses don't spread quickly at all (though talk of them often does!). Those that do spread widely are able to do so for a variety of reasons. A large target population--millions of compatible computers--helps. A large virus population helps. Vendors whose quality assurance relies on, for example, outdated scanners, help. Users who gratuitously install new software on their systems without making any attempt to test for viruses help. All of these things are factors.
There are two main types of viruses?
1. Worms
2. Trojan horse
Worm viruses are a common virus that generally duplicates itself before it spread in networks. It is a self-contained program (or set of programs), that is able to spread functional copies of itself or its segments to other Computer systems (usually via network connections).Note that unlike viruses, worms do not need to attach themselves to a host program. There are two types of worms--host computer worms and network worms.
Trojan horse is a program that does something undocumented that the programmer intended, but that some users would not approve of if they knew about it. According to some people, a virus is a particular case of a Trojan horse, namely one which is able to spread to other programs.
Protecting against Trojans
PREVENTION is the key. Don't open unanticipated file attachments from unknown sources. If you know the source, double check with them and make sure they intended to send it. Ask them exactly what it is and why you need it. If it is a game or frivolous application, delete it. Save any attachment you have a need to open and scan it with an up-to-date antivirus scanner before you launch it.
How can they be prevented?
Viruses can be prevented by taking sensible precautions, including:
- Using up to date antivirus software. E-mail attachments are now the biggest source of virus spread and many e-mail servers are now installed with anti-virus software.
- not allowing other users to use their own floppy disks on your system
- not allowing users to take the company's disks home to use on their own PC
- only downloading files from reputable Internet sites
- write-protecting disks
- avoiding software from unreliable sources
- backing up data regularly
Anti-virus software can inspect computer files and e-mail attachments for viruses and remove or quarantine any which are found.
Where viruses come from?
Viruses are codes in many forms. They are created by programmers even called hackers, that take advantage of this program to make harm to others or just for “joking”. Viruses are also created to spy and also to steal confidential information about individuals or companies, and then these information are sold on the internet.
What are hackers?
Hackers or programmers used codes to create programs. They create programs to make life become better. Nowadays I.T becomes an important thing in our society. This is the future some peoples. There are two types of hackers, the first one is name under white hackers and the other one black hackers.
The white hackers use their knowledge about codes and programming and algorithms to create programs that will improve the way of working. Businesses use computers as an important tool with all its database and programs. Also they use it as a mean of communication.eg doing video conferencing.
On the other hand there is the black hackers, the also create programs but for horrible reason. They create programs like Genvir, Virus Construction Set (VCS), Instant Virus Production Kit (IVP) to generate viruses that will spy or damage vulnerable data. These tools above are also developing by anti-virus developer or companies in lab to test their product.
Virus Construction Set
The first virus generator was VCS, written in 1990. The authors of the kit were members of the Verband Deutscher Virenliebhaber (the Association of German Virus Lovers).
VCS was a rather simple kit. All viruses that the kit can generate are 1,077 bytes and saved to VIRUS.COM on the disk. The user's only options are to specify the name of a text file with a message and to set a generation number to display that message. The VCS viruses can only infect DOS COM files. The payload of the virus is to kill AUTOEXEC.BAT and CONFIG.SYS files and display the user's message.
VCS viruses are simple but encrypted. The only remarkable feature of VCS viruses is that they can check whether the Flu Shot behavior blocker is loaded in memory and avoid infecting if it is.
VCS viruses are simple but encrypted. The only remarkable feature of VCS viruses is that they can check whether the Flu Shot behavior blocker is loaded in memory and avoid infecting if it is.
Why do People Create Computer Viruses?
There are hundreds of thousands of viruses out there (if not millions) and they often designed for different objectives. Most of them fall under the following categories:
- To take control of a computer and use it for specific tasks
- To generate money
- To steal sensitive information (credit card numbers, passwords, personal details, data etc.)
- To prove a point, to prove it can be done, to prove ones skill or for revenge purposes
- To cripple a computer or network
How viruses are made?
I used to think that making viruses had something to do with programming skills. I thought writing a program that could copy itself, spread itself, hide in other programs or files, find its way around on all these different computers that surely had to be the summum of programming.
Maybe this once was true. Back in the old days, when viruses ware written in assembler, were small enough to hide in the boot sector of a floppy disk, were able to attach themselves to a file without anyone noticing (and files were quite small those days), had stealth capability, and could influence your hardware directly, bypassing the operating system.
So maybe, maybe in those days, creating viruses could be seen as an achievement, or as a sport. Now, any fool can do it. And judging by the number of viruses, a lot of them do.
Here's how.
1. Search the web for something like "Virus Construction Tool" or "Internet Worm Generator". Download it.
2. Run the program (click on its icon).
3. Fill in the form. Choose interesting names.
4. check the boxes to indicate how you want this virus / worm to spread (e-mail, irc, ...)
5. Choose your options for 'payload'
click "Done".
6. click "create virus" or "generate"
7. Save the file
8. Run it to see if it works.
