Content
Lisbon
- Type
- Virus
- SubType
- File Infector
- Discovery Date
- 11/01/1989
- Length
- 648 Bytes
- Minimum DAT
- 4002 (12/02/1998)
- Updated DAT
- 4645 (12/07/2005)
- Minimum Engine
- 5.1.00
- Description Added
- 11/15/1989
- Description Modified
- 11/15/1989 12:00 AM (PT)
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Characteristics
Lisbon is a file infecting virus. It does not become memory resident. It infects .COM files. The Lisbon virus is a variant of the Vienna virus. The virus is very similar to Vienna, except that the virus has been altered in order to avoid virus identification/detection files which could identify the Vienna virus.
Each time a file infected with Lisbon is executed, the virus infects or corrupts one .COM file in the current directory.
Additional Comments:
The Lisbon virus is a strain of the Vienna virus first isolated by Jean Luz in Portugal in November, 1989. The virus is very similar to Vienna, except that the virus has been altered in order to avoid virus identification/detection programs which could identify the Vienna virus. When a program infected with Lisbon is executed, the virus will infect or corrupt one .COM file in the current directory. If a program is infected, 648 bytes will be added to the programs length with the virus being located at the end of the program. These programs will have the text strings below near the end of the infected program: "@AIDS" "????????COM" If a program was corrupted instead of being infected, the first five characters of the program will be "@AIDS". These corrupted programs will no longer execute properly, usually resulting in a system hang when they are executed. Corrupted files will not have any file length increase since the first five characters were overwritten by the "@AIDS" string. Known variant(s) of Lisbon are:
Symptoms
Infected files contain the following text strings near the end of the infected file:
"@AIDS"
"????????COM"
If a file was corrupted instead of being infected, the first five characters of the file is "@AIDS". These corrupted files will no longer execute properly, usually resulting in a system hang as they are executed. Corrupted files do not have any file length increase since the first five characters were overwritten by the "@AIDS" string.
Infected files increase in length by 648 bytes. The virus is located at the end of the file.
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
Variants
- Lisbon-B
- Lisbon-B2
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 -
Lisbon is a file infecting virus. It does not become memory resident. It infects .COM files. The Lisbon virus is a variant of the Vienna virus. The virus is very similar to Vienna, except that the virus has been altered in order to avoid virus identification/detection files which could identify the Vienna virus.
Each time a file infected with Lisbon is executed, the virus infects or corrupts one .COM file in the current directory.
Additional Comments:
The Lisbon virus is a strain of the Vienna virus first isolated by Jean Luz in Portugal in November, 1989. The virus is very similar to Vienna, except that the virus has been altered in order to avoid virus identification/detection programs which could identify the Vienna virus. When a program infected with Lisbon is executed, the virus will infect or corrupt one .COM file in the current directory. If a program is infected, 648 bytes will be added to the programs length with the virus being located at the end of the program. These programs will have the text strings below near the end of the infected program: "@AIDS" "????????COM" If a program was corrupted instead of being infected, the first five characters of the program will be "@AIDS". These corrupted programs will no longer execute properly, usually resulting in a system hang when they are executed. Corrupted files will not have any file length increase since the first five characters were overwritten by the "@AIDS" string. Known variant(s) of Lisbon are:
Symptoms
Symptoms -
Infected files contain the following text strings near the end of the infected file:
"@AIDS"
"????????COM"
If a file was corrupted instead of being infected, the first five characters of the file is "@AIDS". These corrupted files will no longer execute properly, usually resulting in a system hang as they are executed. Corrupted files do not have any file length increase since the first five characters were overwritten by the "@AIDS" string.
Infected files increase in length by 648 bytes. The virus is located at the end of the file.
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 :
* 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 -
- Lisbon-B
- Lisbon-B2
