Modified by: RonJay Kristoffer Caragay
ALIASES:

TrojanDownloader:Win32/Dofoil.W (Microsoft); Trojan.Win32.Sharik.rva (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Generic35.CDBD (AVG)

 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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 84,480 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 02 Apr 2014

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:

  • %Application Data%\{random foldername}\{random filename}.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
{Random Installed Application Name} = "%Application Data%\{random foldername}\{random filename}.exe"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}iness.com
  • {helplinks URL of installed program}

However, as of this writing, the said sites are inaccessible.

NOTES:

It connects to non-malicous URL:

  • www.msn.com

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.704.05
FIRST VSAPI PATTERN DATE: 03 Apr 2014
VSAPI OPR PATTERN File: 10.705.00
VSAPI OPR PATTERN Date: 03 Apr 2014

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 value

[ 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\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • {Random Installed Application Name} = "%Application Data%\{random foldername}\{random filename}.exe"

Step 5

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