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TROJ_SMOKE.JH
Aliases: Trojan-Downloader.Win32.Injecter.jqs (Kaspersky); TrojanDownloader:Win32/Dofoil.O (Microsoft)
Malware type: Trojan
Destructive: No
Platform: Windows 2000, Windows XP, Windows Server 2003
Encrypted: Yes
In the wild: Yes

Overview


This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Technical Details


File size: Varies
File type: EXE
Memory resident: Yes
Initial samples received date: 15 Mar 2012
Payload: Downloads files

Arrival Details

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Trojan drops the following copies of itself into the affected system:

  • %User Profile%\Application Data\E6F0DC.exe

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

It stays resident in memory by creating the following process(es):

  • svchost.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{random} = %User Profile%\Application Data\E6F0DC.exe

Download Routine

This Trojan accesses the following websites to download files:

  • {BLOCKED}ok.in

Trend Micro detects the dowloaded file as:

  • TROJ_SINOWAL.SMF

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This Trojan connects to the following URL(s) to check for an Internet connection:

  • www.google.com

Solution


Minimum scan engine: 9.200
First VSAPI Pattern File: *under processing

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_SMOKE.JH

    TROJ_SINOWAL.SMF

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
    • {random} = %User Profile%\Application Data\E6F0DC.exe

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_SMOKE.JH. 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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Analysis By: Roland Marco Dela Paz

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