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.
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Minimum DAT
4002 (1998-12-02) Updated DAT4002 (1998-12-02) |
Minimum Engine
5.1.00 File Length389 Bytes |
Description Added
1993-03-15 Description Modified1993-03-15 |
Malware Proliferation
Characteristics
Upon infection, the Bad.389 virus becomes memory resident as a low system memory Terminate-and-Stay Resident (TSR) of 544 bytes. Interrupt 21 is hooked by the virus.
Once memory resident, the Bad.389 virus will infect .COM files, as they are executed.
Additional Comments:
The Bad-389 virus was submitted in March, 1993. Its origin or point
of isolation is unknown. Bad-389 is a memory resident infector of
.COM programs, including COMMAND.COM.
When the first Bad-389 infected program is executed, the Bad-389
virus will install itself memory resident as a low system memory
TSR of 544 bytes. Interrupt 21 will be hooked by the virus. Bad-389
cannot determine when it is already memory resident, so it will
reinfect memory each time an infected program is executed, taking
up an additional 544 bytes of memory.
Once memory resident, the Bad-389 virus will infect .COM programs,
including COMMAND.COM, when they are executed. Infected programs
will have a file length increase of 389 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 set to the current system
date and time when infection occurred. The following text string
is visible within the viral code in all Bad-389 infected programs:
"Bad command or file name"
Symptoms
"Bad command or file name"
Bad-389 cannot determine when it is already memory resident, it reinfects memory each time an infected file is executed, taking up an additional 544 bytes of memory.
Infected files have a file length increase of 389 bytes. The virus is located at the end of the file. The file's date and time in the DOS disk directory listing is set to the current 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 :
* 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
Bad.595