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

Pinworm is a memory resident, polymorphic, 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. Interrupt 12's return is moved. Interrupt 21 is hooked by the virus in memory.

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

Additional Comments:
The Pinworm virus was received in August, 1994. Its origin or point of isolation is unknown. Pinworm is a memory resident, polymorphic virus which infects .COM and .EXE programs, including COMMAND.COM. When the first Pinworm infected program is executed, this virus will install itself 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 6,144 bytes. Interrupt 21 will be hooked by the virus in memory. Once the Pinworm virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs increase in size by approximately 2,174 to 2,242 bytes. The virus will be located at the end of the file. The program's date and time in the DOS disk directory listing will not be altered. The following text strings are encrypted within the Pinworm viral code: "PINWOrM v1.00 - Coded by ûirogen in April 1994" "CHKLIST.MS CHKLIST.CPS" "PINWOrM.ûg! .. I hope y ou have enjoyed your infestation by the mighty p inworm p arasite" "Fuck you all!" "-ûirogen" The Pinworm virus contains code to delete the files "CHKLIST.MS" and "CHKLIST.CPS" which are used by the Microsoft Anti-Virus and Central Point Anti-Virus programs. It also contains code which checks to see if the program the user is executing ends with the characters "AV", "SCAN", or "OT". If the program the user is attempting to execute ends with any of these characters, the virus will alter the program so that when executed it will result in a "Not enough memory" message and not run. It may also deinstall from memory some versions of Central Point Anti-Virus and Microsoft Anti-Virus. On the 1st of any month, the Pinworm virus activates. At this time, the virus will cause flashing of the Caps Lock, Num Lock, and Scroll Lock keys on the system keyboard. It will also create directories named "PIïWéRM.ûG!". If a DOS directory command is issued on these directories, they will display the following message in 0 byte file names (the file names will have file dates and time corresponding to when the directory was created): "I HOPE Y OU HAVE ENJOYED YOUR INF ESTATION BY THE MIGHTY P INWORM P ARASITEú úúúúúúúú FUCK YOU ALL! -ûIROGEN"

Symptoms

The following text strings are encrypted within the Pinworm viral code:

"PINWOrM v1.00 - Coded by ûirogen in April 1994"
"CHKLIST.MS CHKLIST.CPS"
"PINWOrM.ûg! ..I hope y ou have enjoyed your infestation by the mighty p inworm p arasite"
"Expletive you all!"
"-ûirogen"

The Pinworm virus contains code to delete the files "CHKLIST.MS" and "CHKLIST.CPS" which are used by the Microsoft Anti-Virus and Central Point Anti-Virus files. It also contains code which checks to see if the file the user is executing ends with the characters "AV", "SCAN", or "OT". If the file the user is attempting to execute ends with any of these characters, the virus alters the file so that when executed it results in a "Not enough memory" message and not run. It may also uninstall from memory some versions of Central Point Anti-Virus and Microsoft Anti-Virus.

On the 1st of any month, the Pinworm virus activates. At this time, the virus causes flashing of the Caps Lock, Num Lock, and Scroll Lock keys on the system keyboard. It also creates directories named "PIïWéRM.ûG!". If a DOS directory command is issued on these directories, they display the following message in 0 byte file names (the file names have file dates and time corresponding to when the directory was created):

"I HOPE Y OU HAVE ENJOYED YOUR INF ESTATION BY THE MIGHTY P INWORM P ARASITEú úúúúúúúú 'EXPLETIVE' YOU ALL! -ûIROGEN"

Total system and available free memory decreases by 6,144 bytes. Infected files increase in size by approximately 2,174 to 2,242 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.

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 -

Pinworm is a memory resident, polymorphic, 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. Interrupt 12's return is moved. Interrupt 21 is hooked by the virus in memory.

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

Additional Comments:
The Pinworm virus was received in August, 1994. Its origin or point of isolation is unknown. Pinworm is a memory resident, polymorphic virus which infects .COM and .EXE programs, including COMMAND.COM. When the first Pinworm infected program is executed, this virus will install itself 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 6,144 bytes. Interrupt 21 will be hooked by the virus in memory. Once the Pinworm virus is memory resident, it will infect .COM and .EXE programs when they are executed. Infected programs increase in size by approximately 2,174 to 2,242 bytes. The virus will be located at the end of the file. The program's date and time in the DOS disk directory listing will not be altered. The following text strings are encrypted within the Pinworm viral code: "PINWOrM v1.00 - Coded by ûirogen in April 1994" "CHKLIST.MS CHKLIST.CPS" "PINWOrM.ûg! .. I hope y ou have enjoyed your infestation by the mighty p inworm p arasite" "Fuck you all!" "-ûirogen" The Pinworm virus contains code to delete the files "CHKLIST.MS" and "CHKLIST.CPS" which are used by the Microsoft Anti-Virus and Central Point Anti-Virus programs. It also contains code which checks to see if the program the user is executing ends with the characters "AV", "SCAN", or "OT". If the program the user is attempting to execute ends with any of these characters, the virus will alter the program so that when executed it will result in a "Not enough memory" message and not run. It may also deinstall from memory some versions of Central Point Anti-Virus and Microsoft Anti-Virus. On the 1st of any month, the Pinworm virus activates. At this time, the virus will cause flashing of the Caps Lock, Num Lock, and Scroll Lock keys on the system keyboard. It will also create directories named "PIïWéRM.ûG!". If a DOS directory command is issued on these directories, they will display the following message in 0 byte file names (the file names will have file dates and time corresponding to when the directory was created): "I HOPE Y OU HAVE ENJOYED YOUR INF ESTATION BY THE MIGHTY P INWORM P ARASITEú úúúúúúúú FUCK YOU ALL! -ûIROGEN"

Symptoms

Symptoms -

The following text strings are encrypted within the Pinworm viral code:

"PINWOrM v1.00 - Coded by ûirogen in April 1994"
"CHKLIST.MS CHKLIST.CPS"
"PINWOrM.ûg! ..I hope y ou have enjoyed your infestation by the mighty p inworm p arasite"
"Expletive you all!"
"-ûirogen"

The Pinworm virus contains code to delete the files "CHKLIST.MS" and "CHKLIST.CPS" which are used by the Microsoft Anti-Virus and Central Point Anti-Virus files. It also contains code which checks to see if the file the user is executing ends with the characters "AV", "SCAN", or "OT". If the file the user is attempting to execute ends with any of these characters, the virus alters the file so that when executed it results in a "Not enough memory" message and not run. It may also uninstall from memory some versions of Central Point Anti-Virus and Microsoft Anti-Virus.

On the 1st of any month, the Pinworm virus activates. At this time, the virus causes flashing of the Caps Lock, Num Lock, and Scroll Lock keys on the system keyboard. It also creates directories named "PIïWéRM.ûG!". If a DOS directory command is issued on these directories, they display the following message in 0 byte file names (the file names have file dates and time corresponding to when the directory was created):

"I HOPE Y OU HAVE ENJOYED YOUR INF ESTATION BY THE MIGHTY P INWORM P ARASITEú úúúúúúúú 'EXPLETIVE' YOU ALL! -ûIROGEN"

Total system and available free memory decreases by 6,144 bytes. Infected files increase in size by approximately 2,174 to 2,242 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.

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