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

• M-128

• Tiny-128

Characteristics

Micro 128 is a memory resident, file infecting virus. It infects .COM files, including COMMAND.COM.

Upon infection, this virus becomes memory resident in a hole in memory located in the interrupt area. Interrupt 21 is hooked by the virus.

Once memory resident, Micro 128 infects .COM files as they are executed.

Micro 128 does not do anything besides replicate.

Additional Comments:
The Micro 128 Virus was received in August, 1991. Its origin is unknown. Micro 128 is a memory resident infector of .COM files, including COMMAND.COM. It uses memory resident techniques similar to the Tiny Family of viruses from Bulgaria. The first time a program infected with Micro 128 is executed, this virus will install itself memory resident in a "hole in memory" located in the interrupt area. Interrupt 21 will be hooked by the virus. There will be no change in total system and available free memory. Once memory resident, Micro 128 will infect .COM files, including COMMAND.COM, when they are executed. Infected .COM files will have increased in size by 128 bytes. The virus will be located at the end of the infected program. Infected files will have their file date and time in the disk directory updated to the system date and time when infection occurred. Micro 128 does not do anything besides replicate.

Symptoms

There are no changes in total system and available free memory. Infected .COM files increase in size by 128 bytes. The virus is located at the end of the infected file. Infected files have their file date and time in the disk directory updated to the system date and time 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

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

• M-128

• Tiny-128

Characteristics

Characteristics -

Micro 128 is a memory resident, file infecting virus. It infects .COM files, including COMMAND.COM.

Upon infection, this virus becomes memory resident in a hole in memory located in the interrupt area. Interrupt 21 is hooked by the virus.

Once memory resident, Micro 128 infects .COM files as they are executed.

Micro 128 does not do anything besides replicate.

Additional Comments:
The Micro 128 Virus was received in August, 1991. Its origin is unknown. Micro 128 is a memory resident infector of .COM files, including COMMAND.COM. It uses memory resident techniques similar to the Tiny Family of viruses from Bulgaria. The first time a program infected with Micro 128 is executed, this virus will install itself memory resident in a "hole in memory" located in the interrupt area. Interrupt 21 will be hooked by the virus. There will be no change in total system and available free memory. Once memory resident, Micro 128 will infect .COM files, including COMMAND.COM, when they are executed. Infected .COM files will have increased in size by 128 bytes. The virus will be located at the end of the infected program. Infected files will have their file date and time in the disk directory updated to the system date and time when infection occurred. Micro 128 does not do anything besides replicate.

Symptoms

Symptoms -

There are no changes in total system and available free memory. Infected .COM files increase in size by 128 bytes. The virus is located at the end of the infected file. Infected files have their file date and time in the disk directory updated to the system date and time of infection.

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