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TROJ_DROPPER.FVY

October 12, 2012
 ALIASES:

TrojanDropper:Win32/Blathla.A (Microsoft); Generic.dx!yiy (McAfee); Adware.Rugo (Symantec); Trojan-Dropper.Win32.Cadro.fon (Kaspersky); Adware.Win32.Rugo.1 (v) (Sunbelt); Suspicious:W32/Malware!Gemini (FSecure)

 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:

353,280 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

16 Dec 2011

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.

Installation

This Trojan creates the following folders:

  • %User Temp%\h8nil4o8\
  • %System%/
  • %User Temp%\g7bujwib\
  • %User Profile%\t\
  • %User Profile%\ad\
  • %Windows%\SoftwareDistribution
  • %Windows%\SoftwareDistribution\DataStore\Logs\
  • %Windows%\SoftwareDistribution\DataStore

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

Autostart Technique

This Trojan registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{3F0E0B46-8442-4cb6-93F6-245430498991}

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\EventLog\Application\
OSTD

Other System Modifications

This Trojan deletes the following files:

  • %System%/e7rd.exe
  • %System%/9el9.dll
  • %System%/9el9.dlltmp
  • %System%/2de1.dll
  • %System%/b79e.dll
  • %Windows%/79e7.bmp
  • %Windows%/e7df.exe
  • %Windows%/92b7.flv
  • %Windows%/df91.rm
  • %System%/2buf.exe
  • %System%/dbc7.dll
  • %System%/dbc7.dlltmp
  • %System%/e7ab.dll
  • %System%/79e7.dll
  • %Windows%/1b6.bmp
  • %Windows%/91b.exe
  • %Windows%/f91.flv
  • %Windows%/e7d.rm
  • %System%/e77d.exe
  • %System%/792r.dll
  • %System%/792r.dlltmp
  • %System%/d29s.dll
  • %System%/9e7d.dll
  • %Windows%/b60u.bmp
  • %Windows%/f91d.exe
  • %Windows%/7dfd.flv
  • %Windows%/9e7a.rm
  • %System%/2bed.exe
  • %System%/727o.dll
  • %System%/727o.dlltmp
  • %System%/2bee.dll
  • %Windows%/df9u.bmp
  • %Windows%/df9d.exe
  • %Windows%/df9d.flv
  • %Windows%/f91a.rm
  • %User Temp%\h8nil4o8\mtv.exe
  • %User Temp%\h8nil4o8\z.lz
  • %User Temp%\h8nil4o8\_uninstall
  • %User Temp%\g7bujwib\.
  • %User Temp%\g7bujwib\..
  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log

(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.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It adds the following registry keys:

HKEY_CLASSES_ROOT\BHO.TttPlayer.1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
BHO.TttPlayer.1\CLSID

HKEY_CLASSES_ROOT\BHO.TttPlayer

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
BHO.TttPlayer\CLSID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
BHO.TttPlayer\CurVer

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}\ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}\VersionIndependentProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}\Programmable

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}\InprocServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0\
FLAGS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0\
0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0\
0\win32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0\
HELPDIR

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}\TypeLib

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}\InprocServer32
ThreadingModel = "apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}\TypeLib
Version = "1.0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
OSTD
EventMessageFile = "%System%\2bed.exe"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
OSTD
TypesSupported = 7

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application
Sources = {random characters}

(Note: The default value data of the said registry entry is WSH.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\h8nil4o8\z.lz
  • %User Temp%\h8nil4o8\_uninstall
  • %User Temp%\h8nil4o8\b.dll.zgx.tmp
  • %User Temp%\h8nil4o8\b.dll.zgx
  • %User Temp%\h8nil4o8\p.dll.zgx.tmp
  • %User Temp%\h8nil4o8\p.dll.zgx
  • %User Temp%\h8nil4o8\s.exe.tmp
  • %User Temp%\h8nil4o8\s.exe
  • %User Temp%\h8nil4o8\mtv.exe.tmp
  • %User Temp%\h8nil4o8\mtv.exe
  • %Windows%\Tasks\ms.job
  • %User Temp%\g7bujwib\2.tmp
  • %User Temp%\g7bujwib\_uninstall
  • %User Temp%\g7bujwib\tmp.exe.tmp
  • %User Temp%\g7bujwib\tmp.exe
  • %Common Startup%\ktv.lnk
  • %System%\19aa
  • %System%\m_CHAR(0x05)_‘| J¿7564-51-28
  • %User Profile%\t\r1635.dat
  • %User Profile%\t\b1635.dat
  • %User Profile%\t\a1635.dat
  • %User Profile%\t\p1635.dat
  • %User Temp%\h8nil4o8\2.dll
  • %User Temp%\h8nil4o8\3.dll
  • %User Temp%\h8nil4o8\4.dll

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %Common Startup% is the system's shared Startup folder, which is usually C:\Windows\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\All Users\Programs\Startup on Windows NT, and C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.. %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.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://122.{BLOCKED}123.cn/1.gif
  • http://122.{BLOCKED}123.cn/ue000/38sw.e?uid=403898357312963336770116
  • http://122.{BLOCKED}123.cn/player/blog.updata?{random characters}
  • http://343.{BLOCKED}s.com/list/2011-10-18/ALL.y
  • http://343.{BLOCKED}s.com/list/bl.y

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Restart in Safe Mode

[ Learn More ]

Step 3

Close all opened browser windows

Step 4

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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application
    • OSTD
  • In HKEY_CLASSES_ROOT
    • BHO.TttPlayer.1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\BHO.TttPlayer.1
    • CLSID
  • In HKEY_CLASSES_ROOT
    • BHO.TttPlayer
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\BHO.TttPlayer
    • CLSID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\BHO.TttPlayer
    • CurVer
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
    • {3F0E0B46-8442-4cb6-93F6-245430498991}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}
    • ProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}
    • VersionIndependentProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}
    • Programmable
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}
    • InprocServer32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}
    • TypeLib
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
    • {9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}
    • 1.0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0
    • FLAGS
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0
    • 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0\0
    • win32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{9988B8C4-FF5B-44F2-8F43-AA5237F82F6F}\1.0
    • HELPDIR
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
    • {A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}
    • ProxyStubClsid
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}
    • ProxyStubClsid32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}
    • TypeLib

Step 5

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_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{3F0E0B46-8442-4cb6-93F6-245430498991}\InprocServer32
    • ThreadingModel="apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A32799DB-6B3B-4AE8-A44B-C6EE79CB9C0A}\TypeLib
    • Version="1.0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\OSTD
    • EventMessageFile="%System%\2bed.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\OSTD
    • TypesSupported=7

Step 6

Restore this modified 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_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application
    • From: Sources={random characters}
      To: Sources=WSH

Step 7

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Temp%\h8nil4o8\
  • %System%/
  • %User Temp%\g7bujwib\
  • %User Profile%\t\
  • %User Profile%\ad\
  • %Windows%\SoftwareDistribution
  • %Windows%\SoftwareDistribution\DataStore\Logs\
  • %Windows%\SoftwareDistribution\DataStore

Step 8

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.
  • %User Temp%\h8nil4o8\z.lz
  • %User Temp%\h8nil4o8\_uninstall
  • %User Temp%\h8nil4o8\b.dll.zgx.tmp
  • %User Temp%\h8nil4o8\b.dll.zgx
  • %User Temp%\h8nil4o8\p.dll.zgx.tmp
  • %User Temp%\h8nil4o8\p.dll.zgx
  • %User Temp%\h8nil4o8\s.exe.tmp
  • %User Temp%\h8nil4o8\s.exe
  • %User Temp%\h8nil4o8\mtv.exe.tmp
  • %User Temp%\h8nil4o8\mtv.exe
  • %Windows%\Tasks\ms.job
  • %User Temp%\g7bujwib\2.tmp
  • %User Temp%\g7bujwib\_uninstall
  • %User Temp%\g7bujwib\tmp.exe.tmp
  • %User Temp%\g7bujwib\tmp.exe
  • %Common Startup%\ktv.lnk
  • %System%\19aa
  • %System%\m_CHAR(0x05)_‘| J¿7564-51-28
  • %User Profile%\t\r1635.dat
  • %User Profile%\t\b1635.dat
  • %User Profile%\t\a1635.dat
  • %User Profile%\t\p1635.dat
  • %User Temp%\h8nil4o8\2.dll
  • %User Temp%\h8nil4o8\3.dll
  • %User Temp%\h8nil4o8\4.dll

Step 9

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DROPPER.FVY. 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 10

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%/e7rd.exe
  • %System%/9el9.dll
  • %System%/9el9.dlltmp
  • %System%/2de1.dll
  • %System%/b79e.dll
  • %Windows%/79e7.bmp
  • %Windows%/e7df.exe
  • %Windows%/92b7.flv
  • %Windows%/df91.rm
  • %System%/2buf.exe
  • %System%/dbc7.dll
  • %System%/dbc7.dlltmp
  • %System%/e7ab.dll
  • %System%/79e7.dll
  • %Windows%/1b6.bmp
  • %Windows%/91b.exe
  • %Windows%/f91.flv
  • %Windows%/e7d.rm
  • %System%/e77d.exe
  • %System%/792r.dll
  • %System%/792r.dlltmp
  • %System%/d29s.dll
  • %System%/9e7d.dll
  • %Windows%/b60u.bmp
  • %Windows%/f91d.exe
  • %Windows%/7dfd.flv
  • %Windows%/9e7a.rm
  • %System%/2bed.exe
  • %System%/727o.dll
  • %System%/727o.dlltmp
  • %System%/2bee.dll
  • %Windows%/df9u.bmp
  • %Windows%/df9d.exe
  • %Windows%/df9d.flv
  • %Windows%/f91a.rm
  • %User Temp%\h8nil4o8\mtv.exe
  • %User Temp%\h8nil4o8\z.lz
  • %User Temp%\h8nil4o8\_uninstall
  • %User Temp%\g7bujwib\.
  • %User Temp%\g7bujwib\..
  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log


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