TROJ_SHEUR.CFJ

April 03, 2014
 ALIASES:

Trojan:Win32/Malagent (Microsoft); Generic.dx (McAfee); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse SHeur.ARZT (AVG)

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

  TECHNICAL DETAILS

File Size:

1,174,016 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Apr 2014

Arrival Details

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

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
foxy = "{malware path and file name} -tray"

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\Conf\Forbidden.cfg

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Foxy Network Client Applications

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Settings

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Client

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\SplitterWnd

HKEY_CLASSES_ROOT\foxy\shell\
open\command

HKEY_CLASSES_ROOT\foxy\DefaultIcon

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Internet Explorer\Low Rights\ElevationPolicy

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Low Rights\ElevationPolicy\
{B019794A-A0D3-4811-88CB-6BF93A23A987}

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
User Agent\Post Platform

HKEY_CURRENT_USER\Software\Foxy\
path\karaoke

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\List

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Client
FoxyIsThere = "1"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Client
FoxyInTray = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Low Rights\ElevationPolicy\
{B019794A-A0D3-4811-88CB-6BF93A23A987}
AppName = "{malware file name}"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Low Rights\ElevationPolicy\
{B019794A-A0D3-4811-88CB-6BF93A23A987}
Policy = "3"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}:*:enabled:foxy"

HKEY_CURRENT_USER\Software\Foxy
ClientID = "Amjx3Dt//kWf+9BUZLxXTw"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\List
Results.Ordering = "000102030405"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\List
Results.Widths = "019000640096006400640064"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\List
Results.Sort = "4"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\List
Results.SortAscend = "0"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Client
FoxyXPos = "16"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Client
FoxyYPos = "1d"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Client
FoxyWidth = "3"

HKEY_CURRENT_USER\Software\Foxy Network Client Applications\
Foxy\Client
FoxyHeight = "226"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://gwc.{BLOCKED}x.com:2108/gwc/cgi-bin/fc?{random characters}

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software
    • Foxy Network Client Applications
  • In HKEY_CURRENT_USER\Software Network Client Applications
    • Foxy
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy
    • Settings
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy
    • Client
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy
    • SplitterWnd
  • In HKEY_CLASSES_ROOT\foxy\shell\open
    • command
  • In HKEY_CLASSES_ROOT\foxy
    • DefaultIcon
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Internet Explorer\Low Rights
    • ElevationPolicy
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Low Rights\ElevationPolicy
    • {B019794A-A0D3-4811-88CB-6BF93A23A987}
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\User Agent
    • Post Platform
  • In HKEY_CURRENT_USER\Software\Foxy\path
    • karaoke
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy
    • List

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • foxy = "{malware path and file name} -tray"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\Client
    • FoxyIsThere = "1"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\Client
    • FoxyInTray = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Low Rights\ElevationPolicy\{B019794A-A0D3-4811-88CB-6BF93A23A987}
    • AppName = "{malware file name}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Low Rights\ElevationPolicy\{B019794A-A0D3-4811-88CB-6BF93A23A987}
    • Policy = "3"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {malware path and file name} = "{malware path and file name}:*:enabled:foxy"
  • In HKEY_CURRENT_USER\Software\Foxy
    • ClientID = "Amjx3Dt//kWf+9BUZLxXTw"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\List
    • Results.Ordering = "000102030405"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\List
    • Results.Widths = "019000640096006400640064"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\List
    • Results.Sort = "4"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\List
    • Results.SortAscend = "0"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\Client
    • FoxyXPos = "16"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\Client
    • FoxyYPos = "1d"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\Client
    • FoxyWidth = "3"
  • In HKEY_CURRENT_USER\Software\Foxy Network Client Applications\Foxy\Client
    • FoxyHeight = "226"

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_SHEUR.CFJ. 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.

Step 6

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System Root%\Conf\Forbidden.cfg


Did this description help? Tell us how we did.