TROJ_MEDFOS.SME

October 09, 2012
 Analysis by: Nikko Tamana
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives as a file that exports the functions of other malware/grayware. It may arrive bundled with malware packages as a malware component. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies files, disabling programs and applications from properly running.

It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

19 Jun 2012

Arrival Details

This Trojan arrives as a file that exports the functions of other malware/grayware.

It may arrive bundled with malware packages as a malware component.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following file(s)/component(s):

  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions.sqlite

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

Other System Modifications

This Trojan modifies the following files:

  • %Application Data%\Mozilla\Firefox\Profiles\4wwmjcqo.default\extensions.ini

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Mozilla\
Firefox\Extensions
{9D7673B2-B93D-11E1-8270-B8AC6F996F26} = "%Application Data%\{9D7673B2-B93D-11E1-8270-B8AC6F996F26}\"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
a = "ODUuMTcuMTMyLjMzOwAA"

Download Routine

This Trojan connects to the following malicious URLs:

  • http://{BLOCKED}dfile.com/file/id=AwAyAAEAXXYJAAEFAJAAAAAAAAAAIwwGEAsAAACyc
    3ad4RE9uay4cIImb5lvVVVVVVVVVVVVVVVVVVVVVQ
    AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
    AAAAAAAAAAAADRW&c=3