Threat Description



Category: Malware
Type: Trojan
Platform: W32
Aliases: Rizal, Trojan.Win16.Rizal


Rizal is a trojan that damages critical system files. The trojan is a Windows NE (16-bit) file 14kb long.


Automatic action

Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.

More scanning & removal options

More information on scanning or removal options is available in the documentation for your F-Secure security product on the Downloads section of our Home - Global site.

You may also refer to the Knowledge Base on the F-Secure Community site for more information.

Contact Support

For further assistance, F-Secure customers can request support online via the Request support or the Chat forms on our Home - Global site.

Technical Details

When run the trojan first adds a big amount of similar command blocks AUTOEXEC.BAT. These commands will clear screen, output the below given messages and wait for key to be pressed.

	-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- 	   R I Z A L I A N    T R O J A N 	PROGRAMMED BY: THE HAMMER HEAD TEAM     Computer Science Dept. Jose Rizal University        Shaw BLVD Mandaluyong City Philppines LARRY CONANAN and BENITO TY 	-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-  

Then the trojan destroys MSDOS.SYS file by zeroing it. This only affects DOS and Windows 9x/ME systems.

After that the trojan starts to copy files from \Windows\Command\ folder to \My Documents\, \Windows\, \Windows\System\, \Windows\System\Iosubsys\ and \Windows\Help\ folders. The copied files have zero length. After restart an affected system could become unusable.

Technical Details:Alexey Podrezov; F-Secure Corp.; September 2001


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