Barrotes
Threat LevelDamageDistribution

Effects 

On January 5 Barrotes activates and carries out the following effects:

• It displays several vertical bars which change color on screen.
• It overwrites the Master Boot Record of the hard disk. As a result, the user will not be able to access the hard disk of the computer infected by this virus.
• Barrotes infects the files with EXE and COM extensions that are run, including the COMMAND.COM file.
• Barrotes goes memory resident in order to ensure it is loaded every time the computer is started up

Infection strategy 

In order to carry out its infection, Barrotes follows the routine below:

Barrotes modifies the following files:

• Files with EXE and COM extensions.
• COMMAND.COM, which is found in the root directory. It modifies this file in order to ensure that it is loaded in memory when the operating system is run. When an infected file is run, the virus goes memory resident and intercepts programs with COM and EXE extension when they are accessed or run. In order to do this, the virus intercepts the interrupt 21h.

Barrotes also overwrites the Master Boot Record of the hard disk. As a result, users will not be able to access the hard disk.

Means of transmission 

Barrotes does not use any specific means to spread. It can reach computers through the usual means used by viruses: CD-ROMs, e-mail messages with infected attachments, computer networks, Internet downloads, FTP, floppy disks, etc.