Virus Encyclopedia

Welcome to the Virus Encyclopedia of Panda Security.


Threat LevelModerate threat
DistributionNot widespread


Jerusalem.B has the following effects on the affected computer:

  • It activates when the system date is Friday 13th and it deletes all the files run on the computer.
  • It infects files with a COMEXE or SYS extension. The size of these files increase. For example, the size of COM files increase by 1813 bytes.
  • It reduces the memory available in the computer.
  • The size of EXE or SYS files increases by between 1808 and 18922 bytes.
  • It causes the computer to slow down.

Infection strategy 

In order to carry out the infection, Jerusalem.B goes memory and resident reroutes the interrupts 21h and 08h.

Jerusalem.B increases the size of the files it infects many times. To be more precise, it increases the size of a file with an EXE, COM or SYS extension every time it is run.

Means of transmission 

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

Further Details  

There are many versions of Jerusalem.B, which include the following: Anarkia, Antivirus, Apocalypse, Bogota, Captain, Trips, etc.