The mistaken understanding of computer virus

In the network life, the computer virus has brought the big threat to us, how to prevent the virus is we very concerned about a topic. In fact, the prevention of computer viruses is not a simple word, in the understanding of some of us there is a big mistake, the following we take a look at the computer virus when we face some of the wrong understanding.

1, on the infected floppy disk dir operation will cause the hard drive is infected (wrong)

If the computer's memory does not have a virus, the computer is infected only after executing a program (file) with a virus. The dir command is a DOS internal command that does not require any external programs (files), so the dir operation on the infected floppy will not infect the virus.

It should be noted, however, that if the computer has a virus (or the computer has already been infected), it may infect a floppy disk if it has a DIR operation on a floppy disk that is not infected. Said it could be infected because some viruses do not spread through the dir operation.

2, change the document to read-only way to avoid fungicide infection (wrong)

Some people think that setting the file to read-only can be very effective against viruses through the attrib of DOS external commands. In fact, to modify the properties of a file only need to call a few DOS interrupts, so that the attrib command to prevent the virus infection and spread almost powerless.

3, virus can infect write-protected disk (wrong)

Since viruses can infect read-only files, many people think that viruses can also modify files on write-protected disks. In fact, a disk drive can determine whether the disk is write-protected, should write to it, all of which is controlled by the hardware, you can physically remove the PC's write protection sensor, but not the software to do this thing.

If your floppy drive is normal, and the write protection of the floppy disk has not been taken down, absolutely will not infect the virus. But if you take it down and use the poison machine dir, it is entirely possible to infect the virus. Note that this dir is infecting a virus from a machine to a floppy disk, rather than infecting the virus from a floppy disk to a machine.

Write protection and file read-only way, the settings file read-only way through the computer, so the virus can plug in the first hand, but write protection must be hand in hand, the virus can not write protection to lose. The computer cannot overwrite the write-protected disk, which cannot be changed by any operation (unless you break the drive).

4, anti-virus software can kill all known viruses (wrong)

Virus infection way a lot of, some virus will forcibly overwrite part of execution program, embed oneself code inside, in order to achieve the goal that does not change the length of infected file, the code that is covered by such virus cannot recover, so this virus cannot be safely killed. The virus destroys some of the contents of the file and does not restore the original file after killing the virus.

5, the use of anti-virus software can be protected from viruses (wrong)

At present, the anti-virus software sold on the market can only be "a show of skill" after the virus is rampant. But before antivirus virus has caused the work delay, the data destruction or other more serious consequences. So, you should choose a perfect anti-virus system, it should not only include common search and kill virus functions, but also include real-time anti-virus function, can real-time monitoring, tracking the various operations of the file, once the virus found, immediately alarm, only in this way to minimize the chance of infection by the virus.

6, the disk file damage is more than the virus (wrong)

The file is damaged for a variety of reasons, power supply voltage fluctuations, electricity loss, magnetization, poor disk quality, hardware errors, other software errors, dust, soot, tea, and even a sneeze can result in data loss. The damage caused by the above documents is more common and serious than the damage caused by the virus.

7, if you do backup, back up the mold, then these backups are useless (wrong)

There are two scenarios: ① floppy Backup: A boot virus is included in the backup. In this case, as long as you do not use this floppy disk to try to start your computer, it will be as safe as a non-toxic backup. ② tape Backup: There is no virus in the data file in the backup, and if the executable contains a virus, the execution file is backed up in white, but the data files in the backup are still available.

8, anti-virus software can prevent any mildew (wrong) anytime and anywhere

Obviously, this anti-virus software does not exist. New viruses continue to appear, requiring anti-virus software to be upgraded quickly. Against the virus, we need a security policy and a sophisticated anti-virus system, using Backup as the first line of defense against the virus, the anti-virus software as a second line of defense. At the same time, the software's timely upgrade is the only way to strengthen the second line of defense. Anti-Virus software is used to help antivirus, it can not be bulletproof bodyguards.