Content
Carioca
- Type
- Virus
- SubType
- File Infector
- Discovery Date
- 11/01/1990
- Length
- 951 Bytes
- Minimum DAT
- 4002 (12/02/1998)
- Updated DAT
- 4002 (12/02/1998)
- Minimum Engine
- 5.1.00
- Description Added
- 11/15/1990
- Description Modified
- 11/15/1990 12:00 AM (PT)
Tab Navigation
Characteristics
Carioca is a memory resident, file infecting virus. It infects .COM files, it does not infect COMMAND.COM.
Upon infection, the virus becomes memory resident as a 1,280 byte low system memory Terminate-and-Stay Resident (TSR). Interrupt 21 is hooked by the virus.
Once the virus is memory resident, any .COM file executed becomes infected with the Carioca virus.
It is not what Carioca does besides replicate.
Additional Comments:
The Carioca virus was submitted in November, 1990. This virus is a memory resident infector of .COM files, it does not infect COMMAND.COM. The first time a program infected with the Carioca virus is executed, the virus will install itself memory resident as a 1,280 byte low system memory TSR. Interrupt 21 will be hooked by the virus. The system's available free memory will decrease by 1,312 bytes. After the virus is memory resident, any .COM file executed (with the exception of COMMAND.COM) will become infected with the Carioca virus. Infected .COM files will show an increase in size of 951 bytes with the virus being located at the end of the infected file. Infected files will have the following hex character string located at the very end of the file: "2EFF1E1A010203CD21". It is unknown if Carioca contains any damage potential. Known variant(s) of Carioca are:
Symptoms
The system's available free memory decreases by 1,312 bytes. Infected .COM files increase in size of 951 bytes. The virus is located at the end of the infected file.
Infected files have the following hex character string located at the very end of the file: "2EFF1E1A010203CD21".
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
- Carioca-B
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 -
Carioca is a memory resident, file infecting virus. It infects .COM files, it does not infect COMMAND.COM.
Upon infection, the virus becomes memory resident as a 1,280 byte low system memory Terminate-and-Stay Resident (TSR). Interrupt 21 is hooked by the virus.
Once the virus is memory resident, any .COM file executed becomes infected with the Carioca virus.
It is not what Carioca does besides replicate.
Additional Comments:
The Carioca virus was submitted in November, 1990. This virus is a memory resident infector of .COM files, it does not infect COMMAND.COM. The first time a program infected with the Carioca virus is executed, the virus will install itself memory resident as a 1,280 byte low system memory TSR. Interrupt 21 will be hooked by the virus. The system's available free memory will decrease by 1,312 bytes. After the virus is memory resident, any .COM file executed (with the exception of COMMAND.COM) will become infected with the Carioca virus. Infected .COM files will show an increase in size of 951 bytes with the virus being located at the end of the infected file. Infected files will have the following hex character string located at the very end of the file: "2EFF1E1A010203CD21". It is unknown if Carioca contains any damage potential. Known variant(s) of Carioca are:
Symptoms
Symptoms -
The system's available free memory decreases by 1,312 bytes. Infected .COM files increase in size of 951 bytes. The virus is located at the end of the infected file.
Infected files have the following hex character string located at the very end of the file: "2EFF1E1A010203CD21".
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 -
- Carioca-B
