Analysis by: Mohammed Malubay
ALIASES:

Trojan:Win32/Azorult.ML!MTB(MICROSOFT); HEUR:Trojan-Ransom.Win32.Stop.gen(KASPERSKY);

 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 connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 356,864 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 10 Jun 2021
Payload: Connects to URLs/IPs, 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 adds the following processes:

  • To delete itself:
    • "%System%\cmd.exe" /c taskkill /im "{Malware Filename}.exe" /f & erase "{Malware Filepath}\{Malware Filename}.exe" & exit
  • If download is successful:
    • "%System%\cmd.exe" /c start /I "" "{4 Random Characters}-{5 Random Characters}-{4 Random Characters}-{5 Random Characters}\{11 Random Numbers}.exe"
    • "%System%\cmd.exe" /c start /I "" "{4 Random Characters}-{5 Random Characters}-{4 Random Characters}-{5 Random Characters}\{11 Random Numbers}.exe" /{mix, eu or us depending on the country}

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

It creates the following folders:

  • %User Temp%\{4 Random Characters}-{5 Random Characters}-{4 Random Characters}-{5 Random Characters}\ → Hidden

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}artners.in/dlc/distribution.php?pub={string} → Depending on the {User Agent} used. It may receive a file or a secondary download link
  • {Received secondary download link}

It saves the files it downloads using the following names:

  • %User Temp%\{4 Random Characters}-{5 Random Characters}-{4 Random Characters}-{5 Random Characters}\{11 Random Numbers}.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Information Theft

This Trojan gathers the following data:

  • Username
  • IP Address
  • Country
  • Keyboard Layout/Language

Other Details

This Trojan connects to the following website to send and receive information:

  • {BLOCKED}n.biz/decision.php?pub={String}
  • {BLOCKED}partners.in/stats/remember.php?pub={String}&user={username}
  • {BLOCKED}partners.in/stats/statistics.php?trackid={track id}&postback={postback value}
  • {BLOCKED}partners.in/stats/itscis.php?pub={String}
  • Where depending on the country the infected machine is located in, {String} can be the following:
    • ustwo
    • euthree
    • mixsix
    • eutwo
    • usthree
    • pmix
    • peu
    • pus
    • umix
    • ueu
    • uus
    • cashmix
    • casheu
    • cashus
    • willmix
    • willeu
    • willus
    • usone
    • mixone
    • euone
    • usfour
    • eufour
    • pux
    • eux
    • mixthree
    • eufive
    • usfive
    • cafive
    • mixfive
    • mixseven
    • euinte
    • usinte
    • cainte
    • mixinte

It does the following:

  • It will terminate and delete itself if it finds any of the following:
    • The following folders:
      • %User Desktop%\Garbage Cleaner
    • The following registry keys:
      • HKEY_CURRENT_USER\Software\GCleaner
    • The system's locale or language:
      • Russian
      • Ukrainian
      • Kazakh
  • It connects to the following url(s) to log the Connecting Machine's IP Address:
    • http://{BLOCKED}ger.org/{characters} → accessible
      • where depending on the {String} used, {Characters} can be the following:
        • /1SbGr7
        • /1S3Jr7
        • /1SVGr7
        • /1SDGr7
        • /1SXGr7
        • /1RGrt7
        • /1B6de7
        • /1B8de7
        • /1B9de7
        • /1exB47
        • /1ecB47
        • /1evB47
        • /1KWC77
        • /1KEC77
        • /1KRC77
        • /11juE
        • /11cuE
        • /11QuE
        • /1SMHr7
        • /1SvGr7
        • /1SZGr7
        • /1xA9f7
        • /1xF9f7
        • /1BaHp7
        • /1Uvu47
        • /1SEGr7
        • /17xdv7
        • /17vdv7
        • /17bdv7
        • /17mdv7
        • /1SGGr7
        • /1stmu7
        • /1ssmu7
        • /1sdmu7
        • /1u3ha7

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

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.804.07
FIRST VSAPI PATTERN DATE: 26 Jun 2021
VSAPI OPR PATTERN File: 16.805.00
VSAPI OPR PATTERN Date: 27 Jun 2021

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.XXPE50FFF045

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

Search and delete these files

[ 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%\{4 Random Characters}-{5 Random Characters}-{4 Random Characters}-{5 Random Characters}\{11 Random Numbers}.exe
DATA_GENERIC
  • Once located, select the file then press SHIFT+DELETE to delete it.
  • Repeat the said steps for all files listed.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7 and Server 2008 (R2).

    • Step 5

    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.
    • %User Temp%\{4 Random Characters}-{5 Random Characters}-{4 Random Characters}-{5 Random Characters}\

    Step 6

    Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.LOADSELL.A. 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 the following Trend Micro Support pages for more information:


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