Threat Description



Aliases:W32/Zar.A@mm, Email-Worm.Win32.Zar.A


Zar.A is a simple massmailer that attempts to spread on emails with subject "Tsunami Donation! Please help!".


Automatic action

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


You may wish to refer to the Support Community for further assistance. You also may also refer to General Removal Instructions for a general guide on alternative disinfection actions.

Technical Details

When run, Zar.A makes three copies of itself with the following names:

  • %WinDir%\raz32.exe
  • %WinDir%\crssr.exe
  • %WinDir%\tsunami.exe

where %WinDir% is Windows folder, for example 'C:\Windows\' on a default installation of Windows XP. The "crssr.exe" file is added to the registry key

 "CaptionMgr32" = "%systemroot%\crssr.exe"

As %systemroot% usually refers to same directory as %Windir%, this registry key ensures that the worm is run at every system startup.

Email spreading

Zar.A tries to find addresses from Microsoft Outlook address book. It uses the MAPI functions for sending infected messages for each of the addresses found in the address book.

The message is composed of subject

"Tsunami Donation! Please help!" 

and message body text

"Please help us with your donation and view the attachment below! We need you!" 

The worm attaches itself in messages using filename "tsunami.exe".


Zar.A attempts a Denial Of Serice attack against by issuing ICMP echo messages (ping) with huge payload.

It can also display a fake error message saying

"Fatal Error: Couldn't initialize setup (CRC)" 


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