arrow_back
search
close

TROJ_DROPPE.UR

December 13, 2013
 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:

354,403 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

13 Dec 2013

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 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\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}

Other System Modifications

This Trojan deletes the following files:

  • %System%\Nservies.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It adds the following registry keys:

HKEY_CLASSES_ROOT\lanren

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0\
FLAGS

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0\
0

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0\
0\win32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0\
HELPDIR

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}\ProxyStubClsid

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}\ProxyStubClsid32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}\TypeLib

HKEY_CLASSES_ROOT\CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}\InprocServer32

HKEY_CLASSES_ROOT\¹¤³Ì1.IE360

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
HideDesktopIcons\ClassicStartMenu

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
HideDesktopIcons\NewStartPanel

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
homepages = "http://{BLOCKED}3.cd/?6"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
url1 = "http://www.{BLOCKED}u.com"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
tihuan1 = "http://www.{BLOCKED}3.com/#1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
url2 = "http://www.{BLOCKED}3.com"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
tihuan2 = "http://www.{BLOCKED}3.com/#1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
url3 = "http://www.{BLOCKED}5.com"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
tihuan3 = "http://www.{BLOCKED}3.com/#1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
url4 = "http://www.{BLOCKED}a.com.cn"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
tihuan4 = "http://www.{BLOCKED}3.com/#1"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
url5 = "http://www.{BLOCKED}3.com"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
lanren
tihuan5 = "http://www.{BLOCKED}3.com/#1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
shell = "explorer.exe,%System%\Iehelp.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}\TypeLib
Version = "1.0"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
ProgID = "¹¤³Ì1.IE360"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
TypeLib = "{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
VERSION = "1.0"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
¹¤³Ì1.IE360
Clsid = "{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
ProxyStubClsid = "{00020424-0000-0000-C000-000000000046}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
ProxyStubClsid32 = "{00020424-0000-0000-C000-000000000046}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
HideDesktopIcons\ClassicStartMenu
{871C5380-42A0-1069-A2EA-08002B30309D} = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
HideDesktopIcons\NewStartPanel
{871C5380-42A0-1069-A2EA-08002B30309D} = "1"

Dropping Routine

This Trojan drops the following files:

  • %System Root%\a.bat
  • %Desktop%\Internet Explorer.lnk
  • %User Profile%\??????Internet Explorer.lnk
  • %User Profile%\Quick Launch\Internet Explorer.lnk

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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

Close all opened browser windows

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_CLASSES_ROOT
    • lanren
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
    • {1ED3D9A8-4F0C-43A4-A53A-7474720FA112}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}
    • 1.0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0
    • FLAGS
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0
    • 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0\0
    • win32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}\1.0
    • HELPDIR
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
    • {1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
    • ProxyStubClsid
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
    • ProxyStubClsid32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
    • TypeLib
  • In HKEY_CLASSES_ROOT\CLSID
    • {E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
    • InprocServer32
  • In HKEY_CLASSES_ROOT
    • ¹¤³Ì1.IE360
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons
    • ClassicStartMenu
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons
    • NewStartPanel

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_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • homepages = "http://{BLOCKED}3.cd/?6"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • url1 = "http://www.{BLOCKED}u.com"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • tihuan1 = "http://www.{BLOCKED}3.com/#1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • url2 = "http://www.{BLOCKED}3.com"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • tihuan2 = "http://www.{BLOCKED}3.com/#1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • url3 = "http://www.{BLOCKED}5.com"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • tihuan3 = "http://www.{BLOCKED}3.com/#1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • url4 = "http://www.{BLOCKED}a.com.cn"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • tihuan4 = "http://www.{BLOCKED}3.com/#1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • url5 = "http://www.{BLOCKED}3.com"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\lanren
    • tihuan5 = "http://www.{BLOCKED}3.com/#1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
    • shell = "explorer.exe,%System%\Iehelp.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}\TypeLib
    • Version = "1.0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
    • ProgID = "¹¤³Ì1.IE360"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
    • TypeLib = "{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
    • VERSION = "1.0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\¹¤³Ì1.IE360
    • Clsid = "{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
    • ProxyStubClsid = "{00020424-0000-0000-C000-000000000046}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
    • ProxyStubClsid32 = "{00020424-0000-0000-C000-000000000046}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\ClassicStartMenu
    • {871C5380-42A0-1069-A2EA-08002B30309D} = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\NewStartPanel
    • {871C5380-42A0-1069-A2EA-08002B30309D} = "1"

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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 Root%\a.bat
  • %Desktop%\Internet Explorer.lnk
  • %User Profile%\??????Internet Explorer.lnk
  • %User Profile%\Quick Launch\Internet Explorer.lnk

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPE.UR. 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 7

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%\Nservies.exe


Did this description help? Tell us how we did.