Analysis by: Jennifer Gumban

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size: 29,006 bytes
File Type: Other
Memory Resident: No
Initial Samples Received Date: 27 Jun 2015

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 file(s)/component(s):

  • C:\Bakdirectory\Expansion.log
  • {Autocad's installation folder}\wdpz.tat

It drops the following copies of itself into the affected system:

  • {Autocad installation folder}\acad.fas
  • {all folders and subfolders from drives C: to Z:}\acad.fas
  • {AutoCad working directory}\acaddoc.fas

It creates the following folders:

  • C:\Bakdirectory

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\ctzl

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\KenFiles\
settings

Download Routine

This Trojan saves the files it downloads using the following names:

  • {Autocad's installation folder}\wdzxcj.fas
  • {Autocad's installation folder}\wdpz.tat

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}s.com/hqzxcj/wdzxcj.dat
  • http://ysywy.{BLOCKED}8.org/ysy.tmp
  • ysyping.{BLOCKED}8.org
  • {BLOCKED}6.{BLOCKED}6.100.100

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.756.05
FIRST VSAPI PATTERN DATE: 27 Jun 2015
VSAPI OPR PATTERN File: 11.757.00
VSAPI OPR PATTERN Date: 28 Jun 2015

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

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_CURRENT_USER\Software
    • ctzl = ""

Step 4

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • C:\Bakdirectory

Step 5

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.
  • C:\Bakdirectory\Expansion.log
  • {Autocad's installation folder}\wdpz.tat
  • {Autocad's installation folder}\wdzxcj.fas
  • {Autocad's installation folder}\wdpz.tat

Step 6

Scan your computer with your Trend Micro product to delete files detected as ACM_KENILFE.SDA. 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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