Analysis by: Cris Nowell Pantanilla
 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

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

  TECHNICAL DETAILS

File Size: 1,349,632 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 23 Aug 2016
Payload: Drops files, Executes files

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following files:

  • %User Temp%\{random}.tmp <- temporary file for creating its drop files, deleted after
  • %Windows%\inf\mtmndkb32.PNF
  • %Windows%\inf\ie11.PNF

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Dropping Routine

This Trojan drops the following files:

  • %System%\{DLL Name}.dll - detected as TROJ_KWAMPIRS.G
    where {DLL name} can be any of the following:
    • wmiamgmt
    • wmiassn
    • wmipadp
    • wmiadrv
    • wmipdpa
    Executes using the following shell code:
    • rundll32.exe "%System%\{DLL name}.dll" ControlTrace -Embedding -k DcomLaunch

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

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

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.732.06
FIRST VSAPI PATTERN DATE: 23 Aug 2016
VSAPI OPR PATTERN File: 12.733.00
VSAPI OPR PATTERN Date: 24 Aug 2016

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

Remove the malware/grayware file dropped/downloaded by TROJ_KWAMPIRS.SMC. (Note: Please skip this step if the threat(s) listed below have already been removed.)

    TROJ_KWAMPIRS.G

Step 3

Search and delete this file

[ 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.  %User Temp%\{random}.tmp
%Windows%\inf\mtmndkb32.PNF
%Windows%\inf\ie11.PNF

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_KWAMPIRS.SMC. 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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