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TROJ_NFLOG.NZU

August 01, 2018
 Analysis by: John Anthony Banes
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Spammed via email, Propagates via software vulnerabilities


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

It does not have any propagation routine.

It does not have any backdoor routine.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

63,488 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

05 Mar 2018

Payload:

Drops files, Connects to URLs/IPs, Downloads files

Arrival Details

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

Installation

This Trojan drops the following files:

  • %Windows%\YahooCache.ini - configuration file
  • %Windows%\NfIpv6.ocx - also detected as TROJ_NFLOG.NZU
  • %System%\NfIpv6.ocx - also detected as TROJ_NFLOG.NZU
  • %User Temp%\svchost.exe - also detected as TROJ_NFLOG.NZU
  • %User Temp%\iexpl001.tmp - (copy of dropped svchost.exe) also detected as TROJ_NFLOG.NZU

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

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 = 32

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP\Security
Security = {hex values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP
ObjectName = LocalSystem

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP\Parameters
ServiceDll = %System%\NfIpv6.ocx

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP
ErrorControl = 1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IPRIP
ImagePath = %System%\svchost.exe -k netsvcs

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

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

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

It saves the files it downloads using the following names:

  • %System%\MSMAPI.OCX

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

As of this writing, the said sites are inaccessible.

Other Details

This Trojan does the following:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.112.04

FIRST VSAPI PATTERN DATE:

06 Mar 2018

VSAPI OPR PATTERN File:

14.113.00

VSAPI OPR PATTERN Date:

07 Mar 2018

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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 5

Search and delete these files

[ Learn More ]
There may be some 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
  • %Windows%\NfIpv6.ocx
  • %System%\MSMAPI.OCX
  • %System%\NfIpv6.ocx
  • %User Temp%\svchost.exe
  • %User Temp%\iexpl001.tmp

Step 6

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