PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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.

It disables Task Manager, Registry Editor, and Folder Options.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 390,716 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 Aug 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.

Installation

This Trojan creates the following folders:

  • %User Profile%\Windows\IEUpdate
  • %System Root%\Recycler
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003

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

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
savedump = "%User Profile%\IEUpdate\savedump.exe "

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
savedump = "%User Profile%\IEUpdate\savedump.exe "

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\tmpA.tmp

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{8f9ca745-7424-c352-1070-8ea29fe69f77}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{8f9ca745-7424-c352-1070-8ea29fe69f77}\Enum

HKEY_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\
Microsoft\Windows\CurrentVersion\
RunOnce

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{8f9ca745-7424-c352-1070-8ea29fe69f77}
4sn3fiOwUnf2C6lcS = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{8f9ca745-7424-c352-1070-8ea29fe69f77}
712lESqyX0C7HGJKnPdh8QBd = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{8f9ca745-7424-c352-1070-8ea29fe69f77}
LZAMyNOmloYSnKcVm04ruGGIfTkd = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Command Processor
AutoRun = "%User Profile%\IEUpdate\savedump.exe "

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002
^tuc\ycd = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002
DS@Cu~d = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002
DS@Busf = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002
ET@Cu~d = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002
ET@Busf = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Outlook Express\5.0\Shared Settings\
Setup\30002
E`Dy}u = "{random values}"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "0"

(Note: The default value data of the said registry entry is 2.)

HKEY_CURRENT_USER\Control Panel\Desktop
SCRNSAVE.EXE = "%User Profile%\IEUpdate\savedump.exe "

(Note: The default value data of the said registry entry is %Windows%\system32\logon.scr.)

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
Run = "%User Profile%\IEUpdate\savedump.exe "

Dropping Routine

This Trojan drops the following files:

  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003\SDI-I5uRSQc9Dz3Bv.dat
  • %User Profile%\IEUpdate\savedump.exe
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003\6tBSgZmJHjsoDH770k.dat
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003\lBt-IUkiXoAoUEq2vWbpwS3KK.dat
  • %User Startup%\savedump.lnk
  • %User Temp%\tmpA.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}5.211.48
  • {BLOCKED}.14.117
  • {BLOCKED}5.211.15
  • {BLOCKED}.238.5
  • {BLOCKED}0.14.119

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.700

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

Enable Registry Editor, Task Manager, and Folder options

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware/spyware.

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories
    • {8f9ca745-7424-c352-1070-8ea29fe69f77}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{8f9ca745-7424-c352-1070-8ea29fe69f77}
    • Enum
  • In HKEY_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\Microsoft\Windows\CurrentVersion
    • RunOnce
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup
    • 30002

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • savedump = "%User Profile%\IEUpdate\savedump.exe "
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • savedump = "%User Profile%\IEUpdate\savedump.exe "
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{8f9ca745-7424-c352-1070-8ea29fe69f77}
    • 4sn3fiOwUnf2C6lcS = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{8f9ca745-7424-c352-1070-8ea29fe69f77}
    • 712lESqyX0C7HGJKnPdh8QBd = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{8f9ca745-7424-c352-1070-8ea29fe69f77}
    • LZAMyNOmloYSnKcVm04ruGGIfTkd = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Command Processor
    • AutoRun = "%User Profile%\IEUpdate\savedump.exe "
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup\30002
    • ^tuc\ycd = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup\30002
    • DS@Cu~d = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup\30002
    • DS@Busf = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup\30002
    • ET@Cu~d = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup\30002
    • ET@Busf = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Outlook Express\5.0\Shared Settings\Setup\30002
    • E`Dy}u = "{random values}"

Step 6

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = "0"
      To: Hidden = ""2""
  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • From: SCRNSAVE.EXE = "%User Profile%\IEUpdate\savedump.exe "
      To: SCRNSAVE.EXE = ""%Windows%\system32\logon.scr""

Step 7

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%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003\SDI-I5uRSQc9Dz3Bv.dat
  • %User Profile%\IEUpdate\savedump.exe
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003\6tBSgZmJHjsoDH770k.dat
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003\lBt-IUkiXoAoUEq2vWbpwS3KK.dat
  • %User Startup%\savedump.lnk
  • %User Temp%\tmpA.exe

Step 8

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 Profile%\Windows\IEUpdate
  • %System Root%\Recycler
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003
  • %System Root%\Recycler\S-1-5-21-1645522239-1292428093-682003330-1003\$ast-S-1-5-21-1645522239-1292428093-682003330-1003

Step 9

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

  • %User Temp%\tmpA.tmp


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