TROJ_NFDROP.A

 Analysis by: Kathleen Notario

 PLATFORM:

Windows 2000, Windows XP, Windows 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 may be dropped by other malware.

It does not have any propagation routine.

It does not have any backdoor routine.

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

It does not have any downloading capability.

It does not have any information-stealing capability.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

18,432 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

11 Oct 2011

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_EXPLHLP.AF

Installation

This Trojan drops the following files:

  • %Windows%\NfIpv6.ocx - detected as TROJ_NFDLOAD.A
  • %Windows%\YahooCache.ini - non-malicious file
  • %System%\NfIpv6.ocx - detected as TROJ_NFDLOAD.A

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %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 drops the following copies of itself into the affected system:

  • %User Temp%\iexpl001.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.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Dropping Routine

This Trojan executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.488.05

FIRST VSAPI PATTERN DATE:

11 Oct 2011

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 the malware/grayware file that dropped/downloaded TROJ_NFDROP.A

    • TROJ_EXPLHLP.AF

Step 3

Remove malware files dropped/downloaded by TROJ_NFDROP.A

    • TROJ_NFDLOAD.A

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.
  • %Windows%\YahooCache.ini

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_NFDROP.A. 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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