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

• Skew

Characteristics

Skew-469 is a memory resident, file infecting virus. It infects .EXE files.

Upon infection, this virus becomes memory resident in a hole in allocated low system memory. It hooks interrupts 1C and 21.

Once the Skew-469 virus is memory resident, it infects .EXE files, as they are executed or opened.

It is not known what Skew-469 does besides replicate.

Additional Comments:
The Skew-469, or Skew, virus was submitted in February, 1993, and is originally from the USSR. Skew-469 is a memory resident infector of .EXE programs. It is a fast infector, quickly spreading on infected systems. When the first Skew-469 virus infected program is executed, this virus will install itself memory resident in a "hole" in allocated low system memory, hooking interrupts 1C and 21. Total system and available free memory, as indicated by the DOS CHKDSK program, will not be altered. Once the Skew-469 virus is memory resident, it will infect .EXE programs when they are executed or opened for any reason. Infected programs will have a file length increase of 469 to 485 bytes with the virus being located at the end of the file. The 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 if Skew-469 does anything besides replicate.

Symptoms

Total system and available free memory are not altered. Infected files have a file length increase of 469 to 485 bytes. The virus is located at the end of the file. The 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.

Aliases

• Skew

Characteristics

Characteristics -

Skew-469 is a memory resident, file infecting virus. It infects .EXE files.

Upon infection, this virus becomes memory resident in a hole in allocated low system memory. It hooks interrupts 1C and 21.

Once the Skew-469 virus is memory resident, it infects .EXE files, as they are executed or opened.

It is not known what Skew-469 does besides replicate.

Additional Comments:
The Skew-469, or Skew, virus was submitted in February, 1993, and is originally from the USSR. Skew-469 is a memory resident infector of .EXE programs. It is a fast infector, quickly spreading on infected systems. When the first Skew-469 virus infected program is executed, this virus will install itself memory resident in a "hole" in allocated low system memory, hooking interrupts 1C and 21. Total system and available free memory, as indicated by the DOS CHKDSK program, will not be altered. Once the Skew-469 virus is memory resident, it will infect .EXE programs when they are executed or opened for any reason. Infected programs will have a file length increase of 469 to 485 bytes with the virus being located at the end of the file. The 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 if Skew-469 does anything besides replicate.

Symptoms

Symptoms -

Total system and available free memory are not altered. Infected files have a file length increase of 469 to 485 bytes. The virus is located at the end of the file. The 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