McAfee > Theat Center > Virus Detail Page

Overview

This is a virus detection. Viruses are programs that self-replicate recursively, meaning that infected systems spread the virus to other systems, which then propagate the virus further. While many viruses contain a destructive payload, it's quite common for viruses to do nothing more than spread from one system to another.

Characteristics

889 is a memory resident, file infecting virus. It infects .COM and .EXE files. It does not infect COMMAND.COM.

Upon infection, the 889 virus becomes memory resident at the top of system memory but below the 640K DOS boundary. It hooks interrupt 21. Interrupt 12's return is not moved.

Once the 889 virus is memory resident, it infects .COM and .EXE files, as they are executed.

It is not known what the 889 virus does besides replicate.

Additional Comments:
The 889 virus was submitted in March, 1993. Its origin or point of isolation is unknown. 889 is a memory resident infector of .COM and .EXE programs, but not COMMAND.COM. When the first 889 infected program is executed, the 889 virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, hooking interrupt 21. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 960 bytes. Interrupt 12's return will not be moved. Once the 889 virus is memory resident, it will infect .COM and .EXE programs, but not COMMAND.COM, when they are executed. Infected .COM programs will have a file length increase of 889 bytes with the virus being located at the end of the file. Infected .EXE programs will increase in size by 889 to 903 bytes with the virus at the end of the file. The infected program's date and time in the DOS disk directory listing will have been updated to the current system date and time when infection occurred. No text strings are visible within the viral code in infected programs. It is unknown what the 889 virus may do besides replicate.

Symptoms

Total system and available free memory decreases by 960 bytes. Infected .COM files have a file length increase of 889 bytes. The virus is located at the end of the file. Infected .EXE files increase in size by 889 to 903 bytes. The virus is located at the end of the file. The infected file's date and time in the DOS disk directory listing are updated to the current system date and time of infection.

No text strings are visible within the viral code in infected files.

Method of Infection

The only way to infect a computer with a file infecting virus is to execute an infected file on the computer. The infected file may come from a multitude of sources including: floppy diskettes, downloads through an online service, network, etc. Once the infected file is executed, the virus may activate.

Removal

All Users :
Script,Batch,Macro and non memory-resident:
Use current engine and DAT files for detection and removal.

PE,Trojan,Internet Worm and memory resident :
Use specified engine and DAT files for detection. To remove, boot to MS-DOS mode or use a boot diskette and use the command line scanner:

Additional Windows ME/XP removal considerations

Users should not trust file icons, particularly when receiving files from others via P2P clients, IRC, email or other mediums where users can share files.

AVERT Recommended Updates :

* Office2000 Updates

* Malformed Word Document Could Enable Macro to Run Automatically (Information/Patch )

* scriptlet.typelib/Eyedog vulnerability patch

* Outlook as an email attachment security update

* Exchange 5.5 post SP3 Information Store Patch 5.5.2652.42 - this patch corrects detection issues with GroupShield

For a list of attachments blocked by the Outlook patch and a general FAQ, visit this link .
Additionally, Network Administrators can configure this update using an available tool - visit this link for more information .

It is very common for macro viruses to disable options within Office applications for example in Word, the macro protection warning commonly is disabled. After cleaning macro viruses, ensure that your previously set options are again enabled.

Variants

Variants

N/A

All Information

Overview -

This is a virus detection. Viruses are programs that self-replicate recursively, meaning that infected systems spread the virus to other systems, which then propagate the virus further. While many viruses contain a destructive payload, it's quite common for viruses to do nothing more than spread from one system to another.

Characteristics

Characteristics -

889 is a memory resident, file infecting virus. It infects .COM and .EXE files. It does not infect COMMAND.COM.

Upon infection, the 889 virus becomes memory resident at the top of system memory but below the 640K DOS boundary. It hooks interrupt 21. Interrupt 12's return is not moved.

Once the 889 virus is memory resident, it infects .COM and .EXE files, as they are executed.

It is not known what the 889 virus does besides replicate.

Additional Comments:
The 889 virus was submitted in March, 1993. Its origin or point of isolation is unknown. 889 is a memory resident infector of .COM and .EXE programs, but not COMMAND.COM. When the first 889 infected program is executed, the 889 virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, hooking interrupt 21. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 960 bytes. Interrupt 12's return will not be moved. Once the 889 virus is memory resident, it will infect .COM and .EXE programs, but not COMMAND.COM, when they are executed. Infected .COM programs will have a file length increase of 889 bytes with the virus being located at the end of the file. Infected .EXE programs will increase in size by 889 to 903 bytes with the virus at the end of the file. The infected program's date and time in the DOS disk directory listing will have been updated to the current system date and time when infection occurred. No text strings are visible within the viral code in infected programs. It is unknown what the 889 virus may do besides replicate.

Symptoms

Symptoms -

Total system and available free memory decreases by 960 bytes. Infected .COM files have a file length increase of 889 bytes. The virus is located at the end of the file. Infected .EXE files increase in size by 889 to 903 bytes. The virus is located at the end of the file. The infected file's date and time in the DOS disk directory listing are updated to the current system date and time of infection.

No text strings are visible within the viral code in infected files.

Method of Infection

Method of Infection -

The only way to infect a computer with a file infecting virus is to execute an infected file on the computer. The infected file may come from a multitude of sources including: floppy diskettes, downloads through an online service, network, etc. Once the infected file is executed, the virus may activate.

Removal -

Removal -

All Users :
Script,Batch,Macro and non memory-resident:
Use current engine and DAT files for detection and removal.

PE,Trojan,Internet Worm and memory resident :
Use specified engine and DAT files for detection. To remove, boot to MS-DOS mode or use a boot diskette and use the command line scanner:

Additional Windows ME/XP removal considerations

Users should not trust file icons, particularly when receiving files from others via P2P clients, IRC, email or other mediums where users can share files.

AVERT Recommended Updates :

* Office2000 Updates

* Malformed Word Document Could Enable Macro to Run Automatically (Information/Patch )

* scriptlet.typelib/Eyedog vulnerability patch

* Outlook as an email attachment security update

* Exchange 5.5 post SP3 Information Store Patch 5.5.2652.42 - this patch corrects detection issues with GroupShield

For a list of attachments blocked by the Outlook patch and a general FAQ, visit this link .
Additionally, Network Administrators can configure this update using an available tool - visit this link for more information .

It is very common for macro viruses to disable options within Office applications for example in Word, the macro protection warning commonly is disabled. After cleaning macro viruses, ensure that your previously set options are again enabled.

Variants

Variants -

N/A