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Panda Protection

Virus Encyclopedia

Welcome to the Virus Encyclopedia of Panda Security.

CIH

Threat LevelModerate threatDamageHighDistributionNot widespread
Common name:CIH
Technical name:BAT/CIH
Threat level:Low
Alias:W95/CIH, PE/CIH, CIH.C, CIHV, WIN95.CIH, W95/CIH, W95/CIH.1003, W95/CIH-10xx, CHERNOBYL, TSHERNOBYL, SPACEFIL
Type:Virus
Effects:  

It deletes the content of the hard disk, preventing the computer from starting. It deletes boot information from the BIOS.

Affected platforms:

Windows 2003/XP/2000/NT/ME/98/95

Detection updated on:Nov. 13, 2002
StatisticsNo
Family:Chernobyl

Brief Description 

    

CIH is a resident virus that activates every April 26. It was given this name because the date coincides with the commemoration of the nuclear disaster that took place in Chernobyl in 1986.

This virus is extremely dangerous, as it deletes the content of the hard drive, preventing Windows NT/98/95 computers from starting up. It also infects files with an EXE extension, but only in Windows 98/95 computers.

In computers with an Intel Pentium microprocessor, it deletes the content of the BIOS.

In order to spread it uses several means of transmission, but it does not use a specific method.

Visible Symptoms 

    

After CIH has infected a computer, various symptoms can be noticed:

  • When the computer is started up, the following message is displayed:

    DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER

    This message indicates that the computer cannot be started. The reason for this is that CIH has formatted the hard disk.
  • If the computer is booted from another disk and then the C:\ drive is accessed, the following warning is displayed:

    INVALID DRIVE SPECIFICATION

    This means that the system does not recognize the hard disk because it is completely blank.