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

• Ont-730

Characteristics

Ontario 730 is a memory resident, file infecting virus. It infects .COM, .EXE, and .OVL files. It does not infect COMMAND.COM.

Upon infection, this virus becomes memory resident as a low system memory Terminate-and-Stay Resident (TSR) of 1,024 bytes. It hooks interrupt 21.

Once Ontario 730 is memory resident, it may infect .COM, .EXE and .OVL files as they are executed.

Additional Comments:
The Ontario 730, or 730, virus was discovered in Ontario, Canada, in December, 1991. Ontario 730 is a memory resident infector of .COM, .EXE, and overlay files. The first time a program infected with Ontario 730 is executed, this virus will install itself memory resident as a low system memory TSR of 1,024 bytes. It will have hooked interrupt 21. Once Ontario 730 is memory resident, it will infect .COM, .EXE, and when they are executed, though this does not always occur. It does not infect COMMAND.COM. Programs infected with Ontario 730 will have a file length increase of 730 to 744 bytes. The virus will be located at the end of the infected file. The file's date and time in the DOS disk directory listing will not be altered. One text string can be found within the viral code of the Ontario 730 virus in infected files: "!=TVu" In advanced infections of the Ontario 730 virus, the file allocation table and master boot sector (partition table) may be damaged by the virus.

Symptoms

The following text string is found within the viral code of the Ontario 730 virus in infected files:

"!=TVu"

The Ontario 730 virus may cause file allocation table and hard disk damage in advanced infections.

Files infected with Ontario 730 have a file length increase of 730 to 744 bytes. The virus is located at the end of the infected 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.

Aliases

• Ont-730

Characteristics

Characteristics -

Ontario 730 is a memory resident, file infecting virus. It infects .COM, .EXE, and .OVL files. It does not infect COMMAND.COM.

Upon infection, this virus becomes memory resident as a low system memory Terminate-and-Stay Resident (TSR) of 1,024 bytes. It hooks interrupt 21.

Once Ontario 730 is memory resident, it may infect .COM, .EXE and .OVL files as they are executed.

Additional Comments:
The Ontario 730, or 730, virus was discovered in Ontario, Canada, in December, 1991. Ontario 730 is a memory resident infector of .COM, .EXE, and overlay files. The first time a program infected with Ontario 730 is executed, this virus will install itself memory resident as a low system memory TSR of 1,024 bytes. It will have hooked interrupt 21. Once Ontario 730 is memory resident, it will infect .COM, .EXE, and when they are executed, though this does not always occur. It does not infect COMMAND.COM. Programs infected with Ontario 730 will have a file length increase of 730 to 744 bytes. The virus will be located at the end of the infected file. The file's date and time in the DOS disk directory listing will not be altered. One text string can be found within the viral code of the Ontario 730 virus in infected files: "!=TVu" In advanced infections of the Ontario 730 virus, the file allocation table and master boot sector (partition table) may be damaged by the virus.

Symptoms

Symptoms -

The following text string is found within the viral code of the Ontario 730 virus in infected files:

"!=TVu"

The Ontario 730 virus may cause file allocation table and hard disk damage in advanced infections.

Files infected with Ontario 730 have a file length increase of 730 to 744 bytes. The virus is located at the end of the infected 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