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

• CDV

• Civil Defence

Characteristics

Shifter is a memory resident infector of the hard disk MBR and .EXE files.

Upon infection, the Shifter virus infects the system hard disk's master boot sector, the sector containing the hard disk partitioning information. The virus does not become memory resident at this time, and will not start infecting files.

The next time the system is booted from the system hard disk, the Shifter virus becomes memory resident at the top of system memory but below the 640K DOS boundary, moving interrupt 12's return.

Once the Shifter virus is memory resident, it infects .EXE files when they are executed.

Additional Comments:
The Shifter virus was submitted in February, 1993. Its origin or point of isolation is unknown. Shifter is a memory resident infector of the hard disk master boot sector (partition table sector) and .EXE programs. When the first Shifter infected program is executed, the Shifter virus will infect the system hard disk's master boot sector, the sector containing the hard disk partitioning information. The virus does not become memory resident at this time, and will not start infecting files. The next time the system is booted from the system hard disk, the Shifter virus will become memory resident at the top of system memory but below the 640K DOS boundary, moving interrupt 12's return. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 7,168 bytes. Once the Shifter virus is memory resident, it will infect .EXE programs when they are executed. Infected programs will have a file length increase of 6,672 bytes with the virus being located at the end of the file. The file's date and time in the DOS disk directory listing will not be altered. No text strings are visible within the Shifter viral code. It is unknown what Shifter does besides replicate.

Symptoms

Total system and available free memory decreases by 7,168 bytes. InFected files have a file length increase of 6,672 bytes. The virus is located at the end of the file. The file's date and time in the DOS disk directory listing are not altered. No text strings are visible within the Shifter viral code.

It is not known what Shifter does besides replicate.

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

• CDV

• Civil Defence

Characteristics

Characteristics -

Shifter is a memory resident infector of the hard disk MBR and .EXE files.

Upon infection, the Shifter virus infects the system hard disk's master boot sector, the sector containing the hard disk partitioning information. The virus does not become memory resident at this time, and will not start infecting files.

The next time the system is booted from the system hard disk, the Shifter virus becomes memory resident at the top of system memory but below the 640K DOS boundary, moving interrupt 12's return.

Once the Shifter virus is memory resident, it infects .EXE files when they are executed.

Additional Comments:
The Shifter virus was submitted in February, 1993. Its origin or point of isolation is unknown. Shifter is a memory resident infector of the hard disk master boot sector (partition table sector) and .EXE programs. When the first Shifter infected program is executed, the Shifter virus will infect the system hard disk's master boot sector, the sector containing the hard disk partitioning information. The virus does not become memory resident at this time, and will not start infecting files. The next time the system is booted from the system hard disk, the Shifter virus will become memory resident at the top of system memory but below the 640K DOS boundary, moving interrupt 12's return. Total system and available free memory, as indicated by the DOS CHKDSK program, will have decreased by 7,168 bytes. Once the Shifter virus is memory resident, it will infect .EXE programs when they are executed. Infected programs will have a file length increase of 6,672 bytes with the virus being located at the end of the file. The file's date and time in the DOS disk directory listing will not be altered. No text strings are visible within the Shifter viral code. It is unknown what Shifter does besides replicate.

Symptoms

Symptoms -

Total system and available free memory decreases by 7,168 bytes. InFected files have a file length increase of 6,672 bytes. The virus is located at the end of the file. The file's date and time in the DOS disk directory listing are not altered. No text strings are visible within the Shifter viral code.

It is not known what Shifter does besides replicate.

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