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:

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

To delete the registry key this malware/grayware created:

Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
In the left panel, double-click the following:
HKEY_CLASSES_ROOT
Still in the left panel, locate and delete the key:
lanren
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib
Still in the left panel, locate and delete the key:
{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib>{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}
Still in the left panel, locate and delete the key:
1.0
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib>{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}>1.0
Still in the left panel, locate and delete the key:
FLAGS
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>TypeLib>{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}>1.0>0
Still in the left panel, locate and delete the key:
win32
Again Still in the left panel, locate and delete the key:
HELPDIR
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>Interface
Still in the left panel, locate and delete the key:
{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>Interface>{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
Still in the left panel, locate and delete the key:
ProxyStubClsid
Again Still in the left panel, locate and delete the key:
ProxyStubClsid32
Again Still in the left panel, locate and delete the key:
TypeLib
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>CLSID
Still in the left panel, locate and delete the key:
{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>CLSID>{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
Still in the left panel, locate and delete the key:
InprocServer32
Again Still in the left panel, locate and delete the key:
¹¤³Ì1.IE360
In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Explorer>HideDesktopIcons
Still in the left panel, locate and delete the key:
ClassicStartMenu
Again Still in the left panel, locate and delete the key:
NewStartPanel
Close Registry Editor.

Step 4

Delete this registry value

[ Learn More ]

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"

To delete the registry value this malware/grayware created:

Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>lanren
In the right panel, locate and delete the entry:
homepages = "http://{BLOCKED}3.cd/?6"
Again In the right panel, locate and delete the entry:
url1 = "http://www.{BLOCKED}u.com"
Again In the right panel, locate and delete the entry:
tihuan1 = "http://www.{BLOCKED}3.com/#1"
Again In the right panel, locate and delete the entry:
url2 = "http://www.{BLOCKED}3.com"
Again In the right panel, locate and delete the entry:
tihuan2 = "http://www.{BLOCKED}3.com/#1"
Again In the right panel, locate and delete the entry:
url3 = "http://www.{BLOCKED}5.com"
Again In the right panel, locate and delete the entry:
tihuan3 = "http://www.{BLOCKED}3.com/#1"
Again In the right panel, locate and delete the entry:
url4 = "http://www.{BLOCKED}a.com.cn"
Again In the right panel, locate and delete the entry:
tihuan4 = "http://www.{BLOCKED}3.com/#1"
Again In the right panel, locate and delete the entry:
url5 = "http://www.{BLOCKED}3.com"
Again In the right panel, locate and delete the entry:
tihuan5 = "http://www.{BLOCKED}3.com/#1"
In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows NT>CurrentVersion>Winlogon
In the right panel, locate and delete the entry:
shell = "explorer.exe,%System%\Iehelp.exe"
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>Interface>{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}>TypeLib
In the right panel, locate and delete the entry:
Version = "1.0"
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>CLSID>{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}
In the right panel, locate and delete the entry:
ProgID = "¹¤³Ì1.IE360"
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>CLSID>{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}>InprocServer32
In the right panel, locate and delete the entry:
ThreadingModel = "Apartment"
Again In the right panel, locate and delete the entry:
TypeLib = "{1ED3D9A8-4F0C-43A4-A53A-7474720FA112}"
Again In the right panel, locate and delete the entry:
VERSION = "1.0"
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>¹¤³Ì1.IE360
In the right panel, locate and delete the entry:
Clsid = "{E83E77F8-AE4A-427D-B7EE-3AAE3AFAABA6}"
In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Classes>Interface>{1EFF1855-A9B3-4101-B832-B2D0A3366F7F}
In the right panel, locate and delete the entry:
ProxyStubClsid = "{00020424-0000-0000-C000-000000000046}"
Again In the right panel, locate and delete the entry:
ProxyStubClsid32 = "{00020424-0000-0000-C000-000000000046}"
In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Explorer>HideDesktopIcons>ClassicStartMenu
In the right panel, locate and delete the entry:
{871C5380-42A0-1069-A2EA-08002B30309D} = "1"
In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Explorer>HideDesktopIcons>NewStartPanel
In the right panel, locate and delete the entry:
{871C5380-42A0-1069-A2EA-08002B30309D} = "1"
Close Registry Editor.

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

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