Analysis by: Erika Bianca Mendoza
 PLATFORM:

Windows 2000, Windows XP,Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

It modifies the affected system's HOSTS files. This prevents users from accessing certain websites.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 66,560 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 21 Apr 2011
Payload: Modifies HOSTS file, Drops files

Arrival Details

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Trojan drops the following component file(s):

  • %System%\w.dll - detected by Trend Micro as TROJ_BAMITAL.CW

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following non-malicious files:

  • %System%\dll
  • %Windows%\Temp\explorer.dat
  • %Windows%\Temp\winlogon.dat
  • %System Root%\Documents and Settings\All Users\Documents\dll

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Its DLL component is injected to the following process(es):

  • iexplore.exe
  • chrome.exe
  • firefox.exe
  • opera.exe

HOSTS File Modification

This Trojan modifies the affected system's HOSTS files to prevent a user from accessing the following websites:

  • 127.0.0.1 82.165.237.14
  • 127.0.0.1 82.165.250.33
  • 127.0.0.1 akamai.avg.com
  • 127.0.0.1 antivir.es
  • 127.0.0.1 anti-virus.by
  • 127.0.0.1 avast.com
  • 127.0.0.1 avg.com
  • 127.0.0.1 avp.com
  • 127.0.0.1 avp.ru
  • 127.0.0.1 avp.ru/download/
  • 127.0.0.1 avpg.crsi.symantec.com
  • 127.0.0.1 backup.avg.cz
  • 127.0.0.1 bancoguayaquil.com
  • 127.0.0.1 bcpzonasegura.viabcp.com
  • 127.0.0.1 bitdefender.com
  • 127.0.0.1 clamav.net
  • 127.0.0.1 comodo.com
  • 127.0.0.1 customer.symantec.com
  • 127.0.0.1 dispatch.mcafee.com
  • 127.0.0.1 download.mcafee.com
  • 127.0.0.1 download.microsoft.com
  • 127.0.0.1 downloads.microsoft.com
  • 127.0.0.1 downloads1.kaspersky-labs.com
  • 127.0.0.1 downloads1.kaspersky-labs.com/products/
  • 127.0.0.1 downloads1.kaspersky-labs.com/updates/
  • 127.0.0.1 downloads2.kaspersky-labs.com
  • 127.0.0.1 downloads2.kaspersky-labs.com/products/
  • 127.0.0.1 downloads2.kaspersky-labs.com/updates/
  • 127.0.0.1 downloads3.kaspersky-labs.com
  • 127.0.0.1 downloads3.kaspersky-labs.com/products/
  • 127.0.0.1 downloads3.kaspersky-labs.com/updates/
  • 127.0.0.1 downloads4.kaspersky-labs.com
  • 127.0.0.1 downloads4.kaspersky-labs.com/products/
  • 127.0.0.1 downloads4.kaspersky-labs.com/updates/
  • 127.0.0.1 downloads5.kaspersky-labs.com
  • 127.0.0.1 downloads5.kaspersky-labs.com/products/
  • 127.0.0.1 downloads5.kaspersky-labs.com/updates/
  • 127.0.0.1 drweb.com
  • 127.0.0.1 emsisoft.com
  • 127.0.0.1 eset.com
  • 127.0.0.1 eset.com/
  • 127.0.0.1 eset.com/download/index.php
  • 127.0.0.1 eset.com/joomla/
  • 127.0.0.1 eset.com/products/index.php
  • 127.0.0.1 eset.es
  • 127.0.0.1 fortinet.com
  • 127.0.0.1 f-prot.com
  • 127.0.0.1 f-secure.com
  • 127.0.0.1 gdata.es
  • 127.0.0.1 go.microsoft.com
  • 127.0.0.1 hacksoft.com.pe
  • 127.0.0.1 ikarus.at
  • 127.0.0.1 kaspersky.com
  • 127.0.0.1 kaspersky.ru
  • 127.0.0.1 kaspersky-labs.com
  • 127.0.0.1 liveupdate.symantec.com
  • 127.0.0.1 liveupdate.symantecliveupdate.com
  • 127.0.0.1 macafee.com
  • 127.0.0.1 mast.mcafee.com
  • 127.0.0.1 mcafee.com
  • 127.0.0.1 microsoft.com
  • 127.0.0.1 msdn.microsoft.com
  • 127.0.0.1 my-etrust.com
  • 127.0.0.1 networkassociates.com
  • 127.0.0.1 nod32.com
  • 127.0.0.1 norman.com
  • 127.0.0.1 norton.com
  • 127.0.0.1 nprotect.com
  • 127.0.0.1 pandasecurity.com
  • 127.0.0.1 pandasoftware.com
  • 127.0.0.1 pctools.com
  • 127.0.0.1 pif.symantec.com
  • 127.0.0.1 pifmain.symantec.com
  • 127.0.0.1 rads.mcafee.com
  • 127.0.0.1 rising-global.com
  • 127.0.0.1 scanner.novirusthanks.org
  • 127.0.0.1 secure.nai.com
  • 127.0.0.1 securityresponse.symantec.com
  • 127.0.0.1 service1.symantec.com
  • 127.0.0.1 sophos.com
  • 127.0.0.1 sunbeltsoftware.com
  • 127.0.0.1 support.microsoft.com
  • 127.0.0.1 symantec.com
  • 127.0.0.1 symantec.com/updates
  • 127.0.0.1 threatexpert.com
  • 127.0.0.1 trendmicro.com
  • 127.0.0.1 u2.eset.com
  • 127.0.0.1 u20.eset.com
  • 127.0.0.1 u3.eset.com
  • 127.0.0.1 u3.eset.com/
  • 127.0.0.1 u4.eset.com
  • 127.0.0.1 u4.eset.com/
  • 127.0.0.1 u7.eset.com
  • 127.0.0.1 update.avg.com
  • 127.0.0.1 update.microsoft.com
  • 127.0.0.1 update.symantec.com
  • 127.0.0.1 updates.symantec.com
  • 127.0.0.1 updates1.kaspersky-labs.com
  • 127.0.0.1 updates2.kaspersky-labs.com
  • 127.0.0.1 updates3.kaspersky-labs.com
  • 127.0.0.1 us.mcafee.com
  • 127.0.0.1 viabcp.com
  • 127.0.0.1 virscan.org
  • 127.0.0.1 virusbuster.hu
  • 127.0.0.1 viruslist.com
  • 127.0.0.1 viruslist.ru
  • 127.0.0.1 virusscan.jotti.org
  • 127.0.0.1 virustotal.com
  • 127.0.0.1 windowsupdate.microsoft.com
  • 127.0.0.1 www.ahnlab.com
  • 127.0.0.1 www.aladdin.com
  • 127.0.0.1 www.antivir.es
  • 127.0.0.1 www.antiy.net
  • 127.0.0.1 www.authentium.com
  • 127.0.0.1 www.avast.com
  • 127.0.0.1 www.avg.com
  • 127.0.0.1 www.avp.com
  • 127.0.0.1 www.avp.ru
  • 127.0.0.1 www.avp.ru/download/
  • 127.0.0.1 www.bitdefender.com
  • 127.0.0.1 www.clamav.net
  • 127.0.0.1 www.comodo.com
  • 127.0.0.1 www.download.mcafee.com
  • 127.0.0.1 www.drweb.com
  • 127.0.0.1 www.emsisoft.com
  • 127.0.0.1 www.eset.com
  • 127.0.0.1 www.eset.com/
  • 127.0.0.1 www.eset.com/download/index.php
  • 127.0.0.1 www.eset.com/joomla/
  • 127.0.0.1 www.eset.com/products/index.php
  • 127.0.0.1 www.fortinet.com
  • 127.0.0.1 www.f-prot.com
  • 127.0.0.1 www.f-secure.com
  • 127.0.0.1 www.gdata.es
  • 127.0.0.1 www.grisoft.com
  • 127.0.0.1 www.ikarus.at
  • 127.0.0.1 www.kaspersky.com
  • 127.0.0.1 www.kaspersky.ru
  • 127.0.0.1 www.kaspersky-labs.com
  • 127.0.0.1 www.macafee.com
  • 127.0.0.1 www.mcafee.com
  • 127.0.0.1 www.microsoft.com
  • 127.0.0.1 www.my-etrust.com
  • 127.0.0.1 www.networkassociates.com
  • 127.0.0.1 www.nod32.com
  • 127.0.0.1 www.norman.com
  • 127.0.0.1 www.norton.com
  • 127.0.0.1 www.nprotect.com
  • 127.0.0.1 www.pandasecurity.com
  • 127.0.0.1 www.pandasoftware.com
  • 127.0.0.1 www.pctools.com
  • 127.0.0.1 www.rising-global.com
  • 127.0.0.1 www.scanner.novirusthanks.org
  • 127.0.0.1 www.sophos.com
  • 127.0.0.1 www.sunbeltsoftware.com
  • 127.0.0.1 www.symantec.com
  • 127.0.0.1 www.symantec.com/updates
  • 127.0.0.1 www.trendmicro.com
  • 127.0.0.1 www.virscan.org
  • 127.0.0.1 www.viruslist.com
  • 127.0.0.1 www.viruslist.ru
  • 127.0.0.1 www.virusscan.jotti.org
  • 127.0.0.1 www.virustotal.com
  • 127.0.0.1 www.windowsupdate.microsoft.com

Other Details

This Trojan deletes itself after execution.

NOTES:

Other Details

It deletes the following registry entry which is related to system restore:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore
DisableSR

  SOLUTION

Minimum Scan Engine: 8.900

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Close all opened browser windows

Step 3

Remove malware files dropped/downloaded by TROJ_MEREDROP.JF

    • TROJ_BAMITAL.CW

Step 4

Restore this deleted registry key/value from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\
CurrentVersion\SystemRestore
DisableSR

Step 5

Remove these strings added by the malware/grayware/spyware in the HOSTS file

[ Learn More ]
    127.0.0.1 82.165.237.14
    127.0.0.1 82.165.250.33
    127.0.0.1 akamai.avg.com
    127.0.0.1 antivir.es
    127.0.0.1 anti-virus.by
    127.0.0.1 avast.com
    127.0.0.1 avg.com
    127.0.0.1 avp.com
    127.0.0.1 avp.ru
    127.0.0.1 avp.ru/download/
    127.0.0.1 avpg.crsi.symantec.com
    127.0.0.1 backup.avg.cz
    127.0.0.1 bancoguayaquil.com
    127.0.0.1 bcpzonasegura.viabcp.com
    127.0.0.1 bitdefender.com
    127.0.0.1 clamav.net
    127.0.0.1 comodo.com
    127.0.0.1 customer.symantec.com
    127.0.0.1 dispatch.mcafee.com
    127.0.0.1 download.mcafee.com
    127.0.0.1 download.microsoft.com
    127.0.0.1 downloads.microsoft.com
    127.0.0.1 downloads1.kaspersky-labs.com
    127.0.0.1 downloads1.kaspersky-labs.com/products/
    127.0.0.1 downloads1.kaspersky-labs.com/updates/
    127.0.0.1 downloads2.kaspersky-labs.com
    127.0.0.1 downloads2.kaspersky-labs.com/products/
    127.0.0.1 downloads2.kaspersky-labs.com/updates/
    127.0.0.1 downloads3.kaspersky-labs.com
    127.0.0.1 downloads3.kaspersky-labs.com/products/
    127.0.0.1 downloads3.kaspersky-labs.com/updates/
    127.0.0.1 downloads4.kaspersky-labs.com
    127.0.0.1 downloads4.kaspersky-labs.com/products/
    127.0.0.1 downloads4.kaspersky-labs.com/updates/
    127.0.0.1 downloads5.kaspersky-labs.com
    127.0.0.1 downloads5.kaspersky-labs.com/products/
    127.0.0.1 downloads5.kaspersky-labs.com/updates/
    127.0.0.1 drweb.com
    127.0.0.1 emsisoft.com
    127.0.0.1 eset.com
    127.0.0.1 eset.com/
    127.0.0.1 eset.com/download/index.php
    127.0.0.1 eset.com/joomla/
    127.0.0.1 eset.com/products/index.php
    127.0.0.1 eset.es
    127.0.0.1 fortinet.com
    127.0.0.1 f-prot.com
    127.0.0.1 f-secure.com
    127.0.0.1 gdata.es
    127.0.0.1 go.microsoft.com
    127.0.0.1 hacksoft.com.pe
    127.0.0.1 ikarus.at
    127.0.0.1 kaspersky.com
    127.0.0.1 kaspersky.ru
    127.0.0.1 kaspersky-labs.com
    127.0.0.1 liveupdate.symantec.com
    127.0.0.1 liveupdate.symantecliveupdate.com
    127.0.0.1 macafee.com
    127.0.0.1 mast.mcafee.com
    127.0.0.1 mcafee.com
    127.0.0.1 microsoft.com
    127.0.0.1 msdn.microsoft.com
    127.0.0.1 my-etrust.com
    127.0.0.1 networkassociates.com
    127.0.0.1 nod32.com
    127.0.0.1 norman.com
    127.0.0.1 norton.com
    127.0.0.1 nprotect.com
    127.0.0.1 pandasecurity.com
    127.0.0.1 pandasoftware.com
    127.0.0.1 pctools.com
    127.0.0.1 pif.symantec.com
    127.0.0.1 pifmain.symantec.com
    127.0.0.1 rads.mcafee.com
    127.0.0.1 rising-global.com
    127.0.0.1 scanner.novirusthanks.org
    127.0.0.1 secure.nai.com
    127.0.0.1 securityresponse.symantec.com
    127.0.0.1 service1.symantec.com
    127.0.0.1 sophos.com
    127.0.0.1 sunbeltsoftware.com
    127.0.0.1 support.microsoft.com
    127.0.0.1 symantec.com
    127.0.0.1 symantec.com/updates
    127.0.0.1 threatexpert.com
    127.0.0.1 trendmicro.com
    127.0.0.1 u2.eset.com
    127.0.0.1 u20.eset.com
    127.0.0.1 u3.eset.com
    127.0.0.1 u3.eset.com/
    127.0.0.1 u4.eset.com
    127.0.0.1 u4.eset.com/
    127.0.0.1 u7.eset.com
    127.0.0.1 update.avg.com
    127.0.0.1 update.microsoft.com
    127.0.0.1 update.symantec.com
    127.0.0.1 updates.symantec.com
    127.0.0.1 updates1.kaspersky-labs.com
    127.0.0.1 updates2.kaspersky-labs.com
    127.0.0.1 updates3.kaspersky-labs.com
    127.0.0.1 us.mcafee.com
    127.0.0.1 viabcp.com
    127.0.0.1 virscan.org
    127.0.0.1 virusbuster.hu
    127.0.0.1 viruslist.com
    127.0.0.1 viruslist.ru
    127.0.0.1 virusscan.jotti.org
    127.0.0.1 virustotal.com
    127.0.0.1 windowsupdate.microsoft.com
    127.0.0.1 www.ahnlab.com
    127.0.0.1 www.aladdin.com
    127.0.0.1 www.antivir.es
    127.0.0.1 www.antiy.net
    127.0.0.1 www.authentium.com
    127.0.0.1 www.avast.com
    127.0.0.1 www.avg.com
    127.0.0.1 www.avp.com
    127.0.0.1 www.avp.ru
    127.0.0.1 www.avp.ru/download/
    127.0.0.1 www.bitdefender.com
    127.0.0.1 www.clamav.net
    127.0.0.1 www.comodo.com
    127.0.0.1 www.download.mcafee.com
    127.0.0.1 www.drweb.com
    127.0.0.1 www.emsisoft.com
    127.0.0.1 www.eset.com
    127.0.0.1 www.eset.com/
    127.0.0.1 www.eset.com/download/index.php
    127.0.0.1 www.eset.com/joomla/
    127.0.0.1 www.eset.com/products/index.php
    127.0.0.1 www.fortinet.com
    127.0.0.1 www.f-prot.com
    127.0.0.1 www.f-secure.com
    127.0.0.1 www.gdata.es
    127.0.0.1 www.grisoft.com
    127.0.0.1 www.ikarus.at
    127.0.0.1 www.kaspersky.com
    127.0.0.1 www.kaspersky.ru
    127.0.0.1 www.kaspersky-labs.com
    127.0.0.1 www.macafee.com
    127.0.0.1 www.mcafee.com
    127.0.0.1 www.microsoft.com
    127.0.0.1 www.my-etrust.com
    127.0.0.1 www.networkassociates.com
    127.0.0.1 www.nod32.com
    127.0.0.1 www.norman.com
    127.0.0.1 www.norton.com
    127.0.0.1 www.nprotect.com
    127.0.0.1 www.pandasecurity.com
    127.0.0.1 www.pandasoftware.com
    127.0.0.1 www.pctools.com
    127.0.0.1 www.rising-global.com
    127.0.0.1 www.scanner.novirusthanks.org
    127.0.0.1 www.sophos.com
    127.0.0.1 www.sunbeltsoftware.com
    127.0.0.1 www.symantec.com
    127.0.0.1 www.symantec.com/updates
    127.0.0.1 www.trendmicro.com
    127.0.0.1 www.virscan.org
    127.0.0.1 www.viruslist.com
    127.0.0.1 www.viruslist.ru
    127.0.0.1 www.virusscan.jotti.org
    127.0.0.1 www.virustotal.com
    127.0.0.1 www.windowsupdate.microsoft.com
"

Step 6

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
%System%\dll
%Windows%\Temp\explorer.dat
%Windows%\Temp\winlogon.dat
%System Root%\Documents and Settings\All Users\Documents\dll

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_MEREDROP.JF. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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