computer viruses

 

   OWhat Are Computer Viruses Traditional computer viruses started to appear in the late 80's, and managed to develop due to several factors. The first was the dissemination of the personal computer (PC's). Before 1980, home computers were almost non-existent or used only as a gaming platform. Real computers were rare and reserved for experienced users. During the 1980s, and due to the popularity of the IBM PC, launched in 1982 and the Apple Macintosh, launched in 1984, computers began to be used more and more by merchants, business entities and, of course, by the general population. The factor that led to the creation of viruses was the floppy disk. In the 1980s the programs were small; an operating system, a word processor, and a few programs and documents fit on one or two floppy disks.       MMany computers didn't have a hard disk and, in that case, when the machine was turned on, it loaded the operating system and everything else through floppy disks. Viruses took advantage of this fact to multiply and create the first self-replicating programs. Another factor was the use of online forums, known as “bulletin boards” or “BBS”. People could access these forums via a modem connection and download all kinds of programs. These forums were used by computer viruses and trojans to spread. The source Virus writers have to write the computer code for the virus, as well as test that code to be sure it works and that it will spread properly. It remains then to release the virus to a certain target, whether it be a specific entity or the general public. That programmer also designates the purpose of this virus, from a simple message to the destruction of data or the hard disk. But, after all, what motivates these people? At least three reasons are pointed out. The first stems from the same psychology that drives vandalism and terrorism. In these people resides a destructive and malicious essence. And if the person in question understands computer science and programming, then they channel their energy and creativity into the creation of viruses. The second has to do with the emotion of seeing things explode, the chain reaction and its consequences. Many people have a certain fascination with explosions and mass destruction. Creating a virus that spreads quickly is a bit of that — a bomb on every computer — and the more computers affected, the bigger and more “fun” the explosion will be. The third reason involves breaching property rights, showing system vulnerabilities, or achieving “impenetrable”. A virus creator who discovers a security flaw in the system that can be exploited, instead of informing those responsible for the development or maintenance of the system in question, develops a virus that will take advantage of this flaw either for destruction or general failure (crash ) of the system. From the point of view of the virus creator, this shows his genius and paves the way for others to create more viruses on the same fault.Bill Gates This logic is used essentially against companies like Microsoft, which develops operating systems (Windows) . It spends millions on security and development, so that its systems are constantly updated and aware of vulnerabilities that are being exploited and disclosed by others. Unfortunately, the damage caused by computer viruses is very real. Losing all the information on the hard disk is something any user fears. Even when damage is more limited, users are often forced to spend time and resources cleaning and restoring their system. Large companies lose millions with these attacks, both in lost data, as in damaged programs and hours spent in a non-productive way. For this reason, new programs and forms of prevention against viruses are developed every month. ? In computing, a program that reproduces itself and is transferred from one computer to another without the user noticing it can be a virus.THEmost of these programs (viruses are programs) are created to destroy data or immobilize systems operation. They are transmitted in files contained on CDs, USB sticks, external disks or in online transmissions. The virus attacks by attaching itself to a certain program already installed on the computer, so that when it starts up, the virus starts with it, spreading an infection. This phenomenon usually occurs without the user's knowledge. By infecting the operating system, a virus can replicate itself and try to infect other computers through various means. A virus can either be a harmless program that does little more than annoy you, or it can go to the extreme of destroying files and making a computer inoperable.Çhowever, a common characteristic to all viruses is the speed with which they spread, contaminating other files and computers connected to the Internet that prove to be more vulnerable. Viruses can be divided into three main types: 1 – demo programs (yes, build a virus can also have an educational purpose!);2 – research programs for knowledge of “viruses” and methods of attack and finally, the worst of all reasons;3 – programs for people with bad intentions. You'll see how we attack! Viruses generally pass from one computer to another by exchanging files on pen drives, for example. They can also pass when you go to get programs from other machines via the internet (downloads). This “infection” is dangerous, as it does not show signs and infects the computer without noticing it. If you discover a virus on your computer, you should immediately try to discover its origin and alert the person who sent it to you. (However, there are already some intelligent viruses that erase themselves from pens after copying themselves to the computer's disk, thus losing track of them and preventing their elimination.) How to Know if You Have a Virus on Your Computer? Viruses try to spread as much as possible until they start showing signs of life. But sometimes signs of an infection can be detected. It is important to use this opportunity to detect and eliminate the virus before it begins its destruction phase. There are several types of symptoms that go through messages, sounds, or graphics. However, the main indication is the change in the size of the files and their content. The decrease in available memory is a good indicator, as the virus has to be there somewhere. The most frequent detection is done through the search for certain signatures (simple sequences of letters specific to each type of virus). But this type of search may fail because there may be another (normal) program with the same signature. Others are detected because of strange functioning, as they are resident in the memory or use up the machine's resources. Anti-Viruses To combat this evil, there are programs that detect the existence of viruses after they have infiltrated a computer, or, preferably, before. The best known are the programs from Panda Software, Norton and McAfee. The most advisable thing is to use several types of virus detectors to ensure better immunity. Because the number of viruses is constantly increasing, it is best to have the most recent versions of these programs. How to prevent «Computer Virus» Infections Be very careful when downloading and installing programs or documents from the internet. received by e-mail, especially if we don't know who sent them. Always use up-to-date anti-virus software. That way we don't lose the information that is stored on the hard drive in case of a virus attack. How to Detect a Virus? Don't panic, act calmly and avoid rushing as much as possible. know more than you):1. Shut down the computer.2. Turn it on again, but this time using a “clean” external disk, protected in terms of writing and with an anti-virus that can remove the virus in question. it will not be active. If the infection is on a CD, do not despair, the trash is not an advisable solution. Through a detector on the hard disk you can easily eliminate it. When detected, some viruses can be safely removed from the computer, while others cause such damage that the solution is to format it again and reinstall all the programs that you had before your computer was infected. All types of viruses are very dangerous and you shouldn't take it easy: a virus can spread to thousands, or even millions, of computers in a few hours! The only solution is prevention. Origin of Computer Viruses Hackers create viruses for several reasons, three of which are most well known: The first stems from the same psychology that drives vandalism and terrorism. In these people resides a destructive and malicious essence. And if the person in question understands computer science and programming, then he channels his energy and creativity to the creation of viruses. The second has to do with the emotion of seeing things explode, the chain reaction and its consequences. Many people have a certain fascination with explosions and mass destruction. Creating a virus that spreads quickly is a bit of that — a bomb on every computer — and the more computers affected, the bigger and more "fun" the explosion will be. The third reason involves breaching property rights, showing system vulnerabilities, or hitting the "impenetrable". A virus creator who discovers a security flaw in the system that can be exploited, instead of informing those responsible for the development or maintenance of the system in question, develops a virus that will take advantage of this flaw either for destruction or general failure (crash ) of the system. From the virus creator's point of view, this shows his genius and paves the way for others to create more viruses over the same flaw. Names of Computer VirusesDisk VirusEffects on PC StonedMichelangeloPing-PongInfect the part of the disk responsible for maintaining the files. Saving or loading a file onto an infected floppy disk would enable the virus to activate, which could infect other floppy disks and the hard drive.

 

 

 

 

 

 

 

 

 

VFile viruses Effects on PCAthenasJerusalemFreddyThese viruses copy themselves to the beginning or end of the file.Infect executable or extension files Multi-Partie VirusEffects on PCWhaleNatasInfects both floppy and executable files. They are extremely sophisticated. The 10 Worst Computer Viruses in History If you are a frequent user of the Internet, you are certainly aware of, or have heard about, computer viruses and some of the consequences they cause worldwide. Well, what exactly is a virus? so what is the reason for so much alarm when talking about them? According to Consumer Reports, computer viruses helped contribute $8.5 billion in losses to consumers in the year 2008. In the past, and with the methods used at the time, viruses depended on humans to spread to others. computers. Someone recorded the virus on a floppy disk and it was enough to distribute it to other people. Nowadays, and with the mass use of the Internet by the majority of the population, a virus is generally transmitted “alone” and can even be said to become autonomous. It can be spread via email, fake links, etc. Melissa In 1999, David L. Smith created a virus based on a Microsoft Word macro and designed to spread via email messages. Smith named her Melissa, saying she was named after an exotic dancer from Florida source: CNN]. The Melissa virus caused recipients to open a document with a message similar to: "Here's the document you asked for, don't show it to anyone else." Once activated, the virus made a copy of itself and automatically replicated itself to the first 50 contacts in the recipient's list. This virus, although it did not seriously affect the Internet, was one of the first to attract the attention of the general public. . ILOVEYOU A year after Melissa, a new threat emerged in the Philippines. Unlike the previous one, this threat came in the form of a worm, an independent program called ILOVEYOU, which was capable of making copies of itself. Initially, this virus circulated on the Internet via email, just like Melissa. The email subject said the message would be a love letter from a secret admirer. The problem lay in the attachment it contained. The attachment had the file named LOVE-LETTER-FOR-YOU.TXT.vbs. According to McAfee, producer of anti-virus software, ILOVEYOU had a wide range of attacks: It made a copy of itself several times and It hid itself in several folders on the hard disk; It added new files to the registry keys; It replaced various types of files with copies of itself; It sent a copy of itself through Internet Relay Chat (IRC) clients and also via email; downloaded an executable called WIN-BUGSFIX.EXE and ran it. Instead of fixing the problem (as its name suggests), this program was an application that stole passwords and sent secret information to the creator of the virus. According to some estimates, ILOVEYOU caused 10 billion dollars in damage. cause computer to computer virus contagion as well as the Internet! Klez The Klez virus marked a new direction for viruses, raising the bar for those that would come later. It was released in late 2001, and variations of it plagued the internet for several months. The Klez worm would infect the computer via an email message, make a copy of itself and automatically send it to the people in the victim's contact list. Some variations of Klez loaded other harmful programs that rendered machines inoperable. Depending on the version, it could act like a normal virus, a worm or a Trojan horse. In addition, it could also disable anti-virus software and pretend to be a virus removal tool. However, you could also select another name from the contact list and put the address in the “From” field of the email client. This is called spoofing. The message appears to have come from one source, when in fact it comes from elsewhere, which means that the recipient of the email can recognize the name of the sender and thus be more receptive to opening it.Code Red and Code Red II The Code Red and Code Red II worms appeared in the summer of 2001. Both exploited vulnerabilities in the WINDOWS 2000 and WINDOWS NT operating systems. That weakness was a buffer overflow problem, which means that when a computer running these operating systems receives more information than the buffer can handle, it starts to overwrite adjacent memory. A Windows 2000 computer infected with the Code Red II worm no longer “obeys its owner”. This happens because it creates a backdoor in the computer's operating system, allowing a remote user to gain access and control the machine. The person behind the virus can access the victim's information or even use the infected computer to commit crimes. This means that the person not only has to deal with a damaged machine, but could also become a suspect for crimes he did not commit. On computers running Windows NT, although they were vulnerable to Code Red worms, the effect of these viruses was not as extreme. They used to crash PCs more than usual, but not more than that. Nimda In 2001, another virus to hit the Internet was the Nimda (admin, backwards) worm. Nimda spread across the web quickly, making it the fastest spreading virus ever. According to Peter Tippett of TruSecure, it took just 22 minutes from the moment it hit the network to reach the top of the list of reported attacks. The main targets of the Nimda worm were web servers. Although it could infect a PC, its real purpose was to slow down Internet traffic. He could surf the Internet using a variety of methods, including email, which helped spread the virus across multiple servers in record time. Nimda would create a backdoor into the victim's operating system, thus allowing the person behind the attack to have access to the same level of functions as any account that had logged into the computer lately. In other words, if a user with limited privileges activated the worm on a computer, the attacker would also have the same limited access to the PC's functions. On the other hand, if the victim was the machine's administrator, the attacker would have complete control over it.

 

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