TROJ_DELF.ORB

 Analysis by: jasperm

 ALIASES:

Microsoft : TrojanDownloader:Win32/Delf.KI; Kaspersky : Trojan-Downloader.Win32.Banload.betz ; Sophos : Mal/Generic-L

 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

385,024 bytes

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

18 Nov 2010

Payload:

Connects to URLs/Ips, Downloads files

Arrival Details

This Trojan may be dropped by other malware.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Trojan drops and executes the following files:

  • %System Root%\control - non malicious file
  • %System Root%\golddat.bat - batch file that executes the downloaded file igfxtrai.exe
  • %System Root%\rejuntin.bat - batch file that executes the downloaded file flowchem.exe
  • %System Root%\hammer.bat - batch file that executes the downloaded file jamesdat.exe

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

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}l.net/img/au.jpg - inaccessible
  • http://{BLOCKED}l.net/img/pt.png
  • http://{BLOCKED}l.net/img/fr.jpg

It saves the files it downloads using the following names:

  • %System Root%\jamesdat.exe - detected as TROJ_AGENT.AUCU
  • %System%\igfxtrai.exe - URL inaccessible
  • %System Root%\flowchem.exe - detected as TROJ_BANKER.SAB

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI PATTERN File:

7.633.80

VSAPI PATTERN Date:

18 Nov 2010

VSAPI PATTERN Date:

11/18/2010 12:00:00 AM

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

Identify and terminate files detected as TROJ_DELF.ORB

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Remove malware files dropped/downloaded by TROJ_DELF.ORB

Step 4

Search and delete this file

[ 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%\golddat.bat
%System Root%\rejuntin.bat 
%System Root%\hammer.bat
%System Root%\control

Step 5

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


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