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.

Aliases

• Quiff.1689

Characteristics

1689 Stealth is a memory resident, stealth, file infecting virus. It infects .COM and .EXE files, including COMMAND.COM.

Upon infection, this virus becomes memory resident at the top of system memory but below the 640K DOS boundary. It hooks interrupts 21, 22, and 2F. Interrupt 12's return is not moved.

Once the 1689 Stealth virus is memory resident, it infects .COM and .EXE files as they are executed.

Additional Comments:
The 1689 Stealth virus was submitted in March, 1993. Its origin or point of isolation is unknown. 1689 Stealth is a memory resident stealth virus which infects .COM and .EXE programs, including COMMAND.COM. When the first 1689 Stealth infected program is executed, this virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, hooking interrupts 21, 22, and 2F. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 1,728 bytes. Interrupt 12's return will not have been moved. Once the 1689 Stealth virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs will have increased in size by 1,689 bytes, but the file length increase is hidden by the virus when it is memory resident. The program's date and time in the DOS disk directory listing will not be altered. Two text strings are visible within the viral code in infected programs: "5V3" "COMEXE" The DOS CHKDSK program will return file allocation errors on all infected programs when the virus is memory resident. The virus does attempt to hide the file alterations so some anti-viral utilities which perform CRC or checksumming will not detect alterations on infected programs when 1689 Stealth is active in memory.

Symptoms

Two text strings are visible within the viral code in infected files:

"5V3"
"COMEXE"

The DOS CHKDSK program returns file allocation errors on all infected files when the virus is memory resident. The virus attempts to hide the file alterations so some anti-viral utilities which perform CRC or checksumming do not detect alterations on infected files when 1689 Stealth is active in memory.

Total system and available free memory decreases by 1,728 bytes. Infected files increase in size by 1,689 bytes. The file length increase is hidden by the virus when it is memory resident (Stealth techniques). The file's date and time in the DOS disk directory listing are not altered.

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.

Aliases

• Quiff.1689

Characteristics

Characteristics -

1689 Stealth is a memory resident, stealth, file infecting virus. It infects .COM and .EXE files, including COMMAND.COM.

Upon infection, this virus becomes memory resident at the top of system memory but below the 640K DOS boundary. It hooks interrupts 21, 22, and 2F. Interrupt 12's return is not moved.

Once the 1689 Stealth virus is memory resident, it infects .COM and .EXE files as they are executed.

Additional Comments:
The 1689 Stealth virus was submitted in March, 1993. Its origin or point of isolation is unknown. 1689 Stealth is a memory resident stealth virus which infects .COM and .EXE programs, including COMMAND.COM. When the first 1689 Stealth infected program is executed, this virus will install itself memory resident at the top of system memory but below the 640K DOS boundary, hooking interrupts 21, 22, and 2F. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 1,728 bytes. Interrupt 12's return will not have been moved. Once the 1689 Stealth virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs will have increased in size by 1,689 bytes, but the file length increase is hidden by the virus when it is memory resident. The program's date and time in the DOS disk directory listing will not be altered. Two text strings are visible within the viral code in infected programs: "5V3" "COMEXE" The DOS CHKDSK program will return file allocation errors on all infected programs when the virus is memory resident. The virus does attempt to hide the file alterations so some anti-viral utilities which perform CRC or checksumming will not detect alterations on infected programs when 1689 Stealth is active in memory.

Symptoms

Symptoms -

Two text strings are visible within the viral code in infected files:

"5V3"
"COMEXE"

The DOS CHKDSK program returns file allocation errors on all infected files when the virus is memory resident. The virus attempts to hide the file alterations so some anti-viral utilities which perform CRC or checksumming do not detect alterations on infected files when 1689 Stealth is active in memory.

Total system and available free memory decreases by 1,728 bytes. Infected files increase in size by 1,689 bytes. The file length increase is hidden by the virus when it is memory resident (Stealth techniques). The file's date and time in the DOS disk directory listing are not altered.

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