TROJ_OFICLA.WD

 Analysis by: jasperm

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. However, as of this writing, the said sites are inaccessible.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

31,232 bytes

File Type:

PE

Memory Resident:

No

Initial Samples Received Date:

21 Sep 2010

Payload:

Downloads files, Drops files

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

However, as of this writing, the said sites are inaccessible.

Installation

This Trojan is injected into the following processes running in memory:

  • SVCHOST.EXE

Autostart Technique

This Trojan modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = Explorer.exe rundll32.exe hyli.igo atkhnt

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

It drops the following files:

  • %System%\hyli.igo - detected as TROJ_SASFIS.AE

(Note: %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.)

Other System Modifications

This Trojan adds the following registry keys as part of its installation routine:

HKEY_CLASSES_ROOT\idid

Other Details

This Trojan connects to the following website to send and receive information:

  • {BLOCKED}ader.ru

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI PATTERN File:

7.479.80

VSAPI PATTERN Date:

21 Sep 2010

VSAPI PATTERN Date:

9/21/2010 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

Remove malware files dropped/downloaded by TROJ_OFICLA.WD

Step 3

Identify and delete files detected as TROJ_OFICLA.WD using either the Startup Disk or Recovery Console

[ Learn More ]

Step 4

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\Windows NT\CurrentVersion\Winlogon
    • From: Shell = Explorer.exe rundll32.exe hyli.igo atkhnt
      To: Shell = Explorer.exe

Step 5

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_CLASSES_ROOT
    • idid

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_OFICLA.WD. 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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