Threat Description

Zafi.A

Details

Aliases: Zafi.A, W32/Zafi.A@mm, I-Worm.Kapes, W32.Erkez.A@mm
Category: Malware
Type: Email-Worm
Platform: W32

Summary


Zafi is a mass-mailing worm that sends infected emails with Hungarian text and an attachment disguised as a link.The worm sends emails only to addresses that end with .hu so it is not likely to spread outside Hungary.Zafi was programmed to be active only in April and will cease to work starting from the 1st of May.



Removal


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 further assistance.

Eliminating a Local Network Outbreak

If the infection is in a local network, please follow the instructions on this webpage:



Technical Details


System Infection

When first run, Zafi copies itself to the Windows System Directory with a random name. The copy is then added to the registry with a random name under

HKLMSoftware\Microsoft\Windows\CurrentVersion\Run

To disguise its presence the worm opens a random link from the user's browser history. This tries to make the user believe that an actual link was opened from the infected email.

Another copy of the worm is created with a random name and '.DLL' extension.

The list of addresses the worm collects is written to several other '.DLL' files in the System Directory.

Email Propagation

Zafi collects email addresses by scanning through files with the following extensions:

htm  wab  txt  dbx  tbb  asp  php  sht  adb  mbx  eml  pmr  

The worms sends infected messages to all addresses that end with '.hu'.

The infected emails have the following structure:

From: [infected@sender] or [kepeslapok@meglep.hu] 
To: [targeted@user] 
Subject: kepeslap erkezett!  
Tisztelt felhaszn¡lo!  
annek kepeslapja erkezett!  
A kepeslap feladoja: Erzsi  
A lapot az alibbi cimen tudja megtekinteni:  http//matav.hu/viewcard/index=p4uo5683535GSb0123fhhf578840f0623cv2  vagy a mellekelt internetlink kattintisival.   
 Ã…€œdv¶zlettel: Matav e-card!  
 http//www.netezz.matav.hu/   

The attachment is named to 'link.matav.hu.viewcard.index42ADR4502HHJeTYWYJDF334GSDEv25546.com'.

Payload

On 1st of May Zafi displays a political message and exits.

The other payload is a routine that terminates processes of different security applications and system tools:

zonalarm.exe  vbsntw.exe  vbcons.exe  pccguide.exe  outpost.exe  regedit.exe  regedit32.exe  navapw32.exe  pcciomon.exe  navdx.exe  navstub.exe  navw32.exe  nc2000.exe  ndd32.exe  netmon.exe  netarmor.exe  netinfo.exe  nmain.exe  nprotect.exe  ntvdm.exe  ostronet.exe  vsmain.exe  vsmon.exe  vsstat.exe  vbust.exe  mcagent.exe  fsav32.exe  fssm32.exe  fsm32.exe  fsbwsys.exe  fsgk32.exe  dfw.exe  tnbutil.exe  taskmgr.exe  winlogon.exe  fvprotect.exe   





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