Analysis by: Michael Cabel
 Modified 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 retrieves the details of the file it downloads from a certain file. It creates an event.

This Trojan may be dropped by other malware.

It does not have any propagation routine.

It does not have any backdoor routine.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 10,240 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 11 Oct 2011

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_NFDROP.A

Autostart Technique

This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP
Type = "20"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP
DisplayName = "IPv6 Stack Local Support"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP\Parameters
ServiceDll = "{Malware Path and Fiel Name}"

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan accesses the following websites to download files:

  • http://www.{BLOCKED}ofa.com/NfLog/Nfile.asp

It saves the files it downloads using the following names:

  • %System%\MSMAPI.OCX - detected as BKDR_NFLOG.A

(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.)

Information Theft

This Trojan does not have any information-stealing capability.

NOTES:

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Other Details

This Trojan requires the existence of the following files to properly run:

  • %Windows%\YahooCache.ini

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

It retrieves the details of the file it downloads from the following file:

  • %Windows%\YahooCache.ini

It creates the following event:

  • NfcoreOk

This malware does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.488.05
FIRST VSAPI PATTERN DATE: 11 Oct 2011
VSAPI OPR PATTERN File: 8.489.00
VSAPI OPR PATTERN Date: 12 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_NFDLOAD.A

Step 3

Remove malware files dropped/downloaded by TROJ_NFDLOAD.A

Step 4

Restart in Safe Mode

[ Learn More ]

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.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • IPRIP

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_NFDLOAD.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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