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TROJ_DELF.SMIB

July 03, 2013
 ALIASES:

Trojan:Win32/Delf.IJ (Microsoft); Generic Delphi.m (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Agent.dwra (Kaspersky); Trojan.Win32.Agent.abzlz (Sunbelt); Trojan.Generic.3827367 (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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

64,000 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

26 May 2012

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.

Other System Modifications

This Trojan deletes the following files:

  • %User Profile%\Quick Launch\Launch Internet Explorer Browser.lnk
  • %Start Menu%\Programs\Internet Explorer.lnk
  • %Windows%\{E17D4~1.BAT
  • %Windows%\racc.bat

(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.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.. %Windows% is the Windows folder, which is usually C:\Windows.)

It adds the following registry keys:

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

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

HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\
Shell

HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\
Shell\Open

HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\
Shell\Open\Command

HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\
Shell\ÊôÐÔ(&R)

HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\
Shell\ÊôÐÔ(&R)\Command

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}

It adds the following registry entries:

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

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

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\ShellFolder
Attributes = "a"

(Note: The default value data of the said registry entry is 20180000.)

Other Details

This Trojan deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

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\HideDesktopIcons
    • NewStartPanel
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons
    • ClassicStartMenu
  • In HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}
    • Shell
  • In HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\Shell
    • Open
  • In HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\Shell\Open
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\Shell
    • ÊôÐÔ(&R)
  • In HKEY_CLASSES_ROOT\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\Shell\ÊôÐÔ(&R)
    • Command
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID
    • {e17d4fc0-5564-11d1-83f2-00a0c90dc849}

Step 3

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

Step 4

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_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{e17d4fc0-5564-11d1-83f2-00a0c90dc849}\ShellFolder
    • From: Attributes = "a"
      To: Attributes = ""20180000""

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_DELF.SMIB. 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.

  • %User Profile%\Quick Launch\Launch Internet Explorer Browser.lnk
  • %Start Menu%\Programs\Internet Explorer.lnk
  • %Windows%\{E17D4~1.BAT
  • %Windows%\racc.bat


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