Trojan.Win32.SMOKELOADER.AF

November 18, 2019
 Analysis by: Carl Maverick Pascual
 ALIASES:

W32/Mokes.AHDZ!tr.bdr (Fortinet) ; Trojan.GenericKD.41993420 (BITDEFENDER)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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 does not have any propagation routine.

It steals certain information from the system and/or the user.

It terminates itself if it detects it is being run in a virtual environment. It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

168,448 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Nov 2019

Payload:

Connects to URLs/IPs, Terminates processes, Steals information

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 copies of itself into the affected system:

  • %Application Data%\{random file name} -> File name is randomly generated based on system information

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It drops the following files:

  • %Application Data%\{random file name} -> Encrypted copy of the download module from the C&C server. File name is randomly generated based on system information
  • %Application Data%\{random file name} -> XML file used to execute the dropped copy in %Application Data%. File name is randomly generated based on system information
  • %User Temp%\{temp file name}.tmp -> Copy of %System%\ntdll.dll

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It adds the following processes:

  • explorer.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • {Randomly generated hash based on system information}
  • opera_shared_counter

It injects codes into the following process(es):

  • explorer.exe

Propagation

This Trojan does not have any propagation routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • x64dbg.exe
  • x32dbg.exe
  • autoruns.exe
  • idaq64.exe
  • idaq.exe
  • ollydbg.exe
  • processhacker.exe
  • procexp.exe
  • procmon.exe
  • tcpview.exe
  • wireshark.exe

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://{BLOCKED}ministries.org/playoff/chmpion4378/hockey.php

Information Theft

This Trojan steals the following information:

  • User Name
  • Computer Name
  • Volume System Information
  • Credentials used in the following protocol:
    • ftp
    • smtp
    • pop3
    • imap
  • Credentials and cookies transferred over HTTP and HTTPS via the following web browser applications:
    • Internet Explorer
    • Microsoft Edge
    • Opera
    • Mozilla Firefox
    • Google Chrome

Stolen Information

This Trojan sends the gathered information via HTTP POST to the following URL:

  • http://{BLOCKED}ministries.org/playoff/chmpion4378/hockey.php

Other Details

This Trojan terminates itself if it detects it is being run in a virtual environment.

It does the following:

  • It checks for the following DLL or modules if existing:
    • sbiedll

    If found, it terminates itself
  • Checks for the presence of known sandbox IDs in the following registry keys:
    • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControLSet\Enum\IDE
    • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControLSet\Enum\SCSI

    where the sandbox IDs could be any of the following
    • qemu
    • virtio
    • vmware
    • vbox
    • xen

    If found, it terminates itself

It deletes itself after execution.

It does not exploit any vulnerability.

It adds the following scheduled tasks:

  • NvNgxUpdateCheckDaily_{Random GUID}
  • Task Action: regsvr32 /s /n /u /i:"%Application Data%\{XML file}" scrobj

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.496.02

FIRST VSAPI PATTERN DATE:

15 Nov 2019

VSAPI OPR PATTERN File:

15.497.00

VSAPI OPR PATTERN Date:

16 Nov 2019

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    • Troj.Win32.TRX.XXPE50FFF032

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

Deleting Scheduled Tasks

The following {Task Name} - {Task to be run} listed should be used in the steps identified below:

  • NvNgxUpdateCheckDaily_{Random GUID} - "regsvr32 /s /n /u /i:"%Application Data%\{XML file} scrobj"

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
    System Tools>Scheduled Tasks.
  2. Locate each {Task Name} values listed above in the Name column.
  3. Right-click on the said file(s) with the aforementioned value.
  4. Click on Properties. In the Run field, check for the listed {Task to be run}.
  5. If the strings match the list above, delete the task.

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

  1. Open the Windows Task Scheduler. To do this:
    • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
    • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
  2. In the left panel, click Task Scheduler Library.
  3. In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
  4. In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
  5. If the said string is found, delete the task.

Step 6

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.
  • %Application Data%\{random file name}
  • %Application Data%\{random file name}
  • %User Temp%\{temp file name}.tmp

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.SMOKELOADER.AF. 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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