The Internet threat alert status is currently normal. At present, no major epidemics or other serious incidents have been recorded by Kaspersky Lab’s monitoring service. Internet threat level: 1


Detected Jul 06 2003 22:57 GMT
Released Jul 06 2003 22:57 GMT
Published Aug 15 2007 07:52 GMT

Technical Details
Removal instructions

Technical Details

This Trojan has a malicious payload. It is a Windows PE EXE file. It is 13,824 bytes in size. It is packed using UPX. The unpacked file is approximately 32KB in size. It is written in C++.


The Trojan also copies its executable file to the Windows system directory under the following names:


In order to ensure that the Trojan is launched automatically when the system is rebooted, the Trojan registers its executable file in the system registry:

"(Default)" = "%System%\NavbwvLw32.Exe"


When launching, the Trojan scans the system for widnows with the following names and terminates them:

Norton AntiVirus
eSafe Desktop Watch
eTrust EZ AntiVirus
Panda AntiVirus Titanium
PC-Cillin 2002
PC-Cillin 2003
F-Secure Anti-Virus
Sophos AntiVirus
ZoneAlarm Pro
Tiny Personal Firewall
McAfee Firewall
Norton Personal FireWall

The Trojan then ceases running.

Removal instructions

If your computer does not have an up-to-date antivirus, or does not have an antivirus solution at all, follow the instructions below to delete the malicious program:

  1. Delete the original Trojan file (the location will depend on how the program originally penetrated the victim machine).
  2. Delete the following system registry key: (see What is a system registry and how do I use it for details on how to edit the registry).
    "(Default)" = "%System%\NavbwvLw32.Exe"
  3. Delete the following files:
  4. Update your antivirus databases and perform a full scan of the computer (download a trial version of Kaspersky Anti-Virus).

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This type of behaviour covers malicious programs that delete, block, modify, or copy data, disrupt computer or network performance, but which cannot be classified under any of the behaviours identified above.

This classification also covers “multipurpose” Trojan programs, i.e. those that are capable of conducting several actions at once and which demonstrate several Trojan behaviours in a single program. This means they cannot be indisputably classified as having any single behaviour.

Other versions


Trojan.Win32.KillAV.an (Kaspersky Lab) is also known as:

  • Virus: W32/BackZat.worm.gen (McAfee)
  • Troj/KillAV-BE (Sophos)
  • Trojan.Killav-19 (ClamAV)
  • W32/KillAV.C (FPROT)
  • Trojan:Win32/Killav.AN (MS(OneCare))
  • Trojan.Siggen.13216 (DrWeb)
  • Win32/KillAV.AN trojan (Nod32)
  • Generic.Malware.SVWk!.83B80AA4 (BitDef7)
  • Trojan.Killav.AII (VirusBuster)
  • Win32:Trojan-gen (AVAST)
  • Trojan.Win32.KillAV (Ikarus)
  • Generic.KIM (AVG)
  • TR/Killav.AN (AVIRA)
  • Trojan Horse (NAV)
  • W32/Killav.AS (Norman)
  • W32/BackZat.worm.gen (NAI)
  • TROJ_Generic (PCCIL)
  • Worm.Lonewolf.b (Rising)
  • TROJ_Generic (TrendMicro)