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TROJ_DELF.CMO

October 10, 2012
 ALIASES:

TrojanDownloader:Win32/Delf.ZXC (Microsoft); Generic Downloader.x!fdj (McAfee); Downloader (Symantec); Trojan-Downloader.Win32.Murlo.lhb (Kaspersky); Trojan-Downloader.Win32.Delf (Sunbelt); Trojan.Generic.KD.196189 (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:

399,360 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

26 Sep 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.

Installation

This Trojan creates the following folders:

  • %System Root%\ProgramDates

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

Other System Modifications

This Trojan deletes the following files:

  • %Temp%\scs3.tmp
  • %Temp%\scs4.tmp
  • %Temp%\scs1.tmp
  • %Temp%\scs6.tmp
  • %Temp%\scs2.tmp
  • %Temp%\scs5.tmp

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "iexplore.exe"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = "4117b81"

(Note: The default value data of the said registry entry is 41107b81.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\ProgramDates\ManageWin.exe
  • %System Root%\ProgramDates\SystemOpera.exe
  • %System Root%\ProgramDates\sysuptad.exe

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}web.com/loja/social/1.jpg
  • http://{BLOCKED}web.com/loja/social/2.jpg
  • http://{BLOCKED}web.com/loja/social/3.jpg

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

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\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: Name = "iexplore.exe"
      To: Name = ""iexplore.exe""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: ID = "4117b81"
      To: ID = ""41107b81""

Step 3

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.
  • %System Root%\ProgramDates\ManageWin.exe
  • %System Root%\ProgramDates\SystemOpera.exe
  • %System Root%\ProgramDates\sysuptad.exe

Step 4

Search and delete this folder

[ 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.
  • %System Root%\ProgramDates

Step 5

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

  • %Temp%\scs3.tmp
  • %Temp%\scs4.tmp
  • %Temp%\scs1.tmp
  • %Temp%\scs6.tmp
  • %Temp%\scs2.tmp
  • %Temp%\scs5.tmp


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