Analysis by: Maria Emreen Viray
 ALIASES:

Ransom:Win32/StopCrypt.MBK!MTB (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Ransomware 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

Tipo de compactação: 510,464 bytes
Tipo de arquivo: EXE
Residente na memória: No
Data de recebimento das amostras iniciais: 18 Sep 2021

Arrival Details

This Ransomware 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 Ransomware drops the following files:

  • %AppDataLocalLow%\sqlite3.dll
  • %AppDataLocalLow%\{Random Characters}
  • %AppDataLocalLow%\{Random Characters}.zip
  • %AppDataLocalLow%\{Random Characters}\AccessibleHandler.dll
  • %AppDataLocalLow%\{Random Characters}\AccessibleMarshal.dll
  • %AppDataLocalLow%\{Random Characters}\IA2Marshal.dll
  • %AppDataLocalLow%\{Random Characters}\MapiProxy.dll
  • %AppDataLocalLow%\{Random Characters}\MapiProxy_InUse.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-file-l1-2-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-file-l2-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-handle-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-heap-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-interlocked-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-libraryloader-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-localization-l1-2-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-memory-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-namedpipe-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-processenvironment-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-processthreads-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-processthreads-l1-1-1.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-profile-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-rtlsupport-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-string-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-synch-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-synch-l1-2-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-sysinfo-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-timezone-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-util-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-conio-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-convert-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-environment-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-filesystem-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-heap-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-locale-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-math-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-multibyte-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-private-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-process-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-runtime-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-stdio-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-string-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-time-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-utility-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\breakpadinjector.dll
  • %AppDataLocalLow%\{Random Characters}\freebl3.dll
  • %AppDataLocalLow%\{Random Characters}\ldap60.dll
  • %AppDataLocalLow%\{Random Characters}\ldif60.dll
  • %AppDataLocalLow%\{Random Characters}\lgpllibs.dll
  • %AppDataLocalLow%\{Random Characters}\libEGL.dll
  • %AppDataLocalLow%\{Random Characters}\mozMapi32.dll
  • %AppDataLocalLow%\{Random Characters}\mozMapi32_InUse.dll
  • %AppDataLocalLow%\{Random Characters}\mozglue.dll
  • %AppDataLocalLow%\{Random Characters}\msvcp140.dll
  • %AppDataLocalLow%\{Random Characters}\nss3.dll
  • %AppDataLocalLow%\{Random Characters}\nssckbi.dll
  • %AppDataLocalLow%\{Random Characters}\nssdbm3.dll
  • %AppDataLocalLow%\{Random Characters}\prldap60.dll
  • %AppDataLocalLow%\{Random Characters}\qipcap.dll
  • %AppDataLocalLow%\{Random Characters}\softokn3.dll
  • %AppDataLocalLow%\{Random Characters}\ucrtbase.dll
  • %AppDataLocalLow%\{Random Characters}\vcruntime140.dll
  • %AppDataLocalLow%\{Random Characters}\{Random Characters}.zip

(Note: %AppDataLocalLow% is the LocalLow Application Data folder, which is usually C:\Users\{user name}\AppData\LocalLow on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • cmd.exe /C timeout /T 10 /NOBREAK > Nul & Del /f /q "{Malware file path and name}"
  • timeout /T 10 /NOBREAK

It creates the following folders:

  • %AppDataLocalLow%\{Random Characters}

(Note: %AppDataLocalLow% is the LocalLow Application Data folder, which is usually C:\Users\{user name}\AppData\LocalLow on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other Details

This Ransomware connects to the following possibly malicious URL:

  • {BLOCKED}.in
  • {BLOCKED}.{BLOCKED}.175.24
  • {BLOCKED}.{BLOCKED}.225.248

  SOLUTION

Mecanismo de varredura mínima: 9.800
Primeiro arquivo padrão VSAPI: 16.974.06
Data do lançamento do primeiro padrão VSAPI: 18 Sep 2021
VSAPI OPR Pattern Version: 16.975.00
VSAPI OPR Pattern veröffentlicht am: 19 Sep 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.XXPE50FFF048

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 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.
  • %AppDataLocalLow%\sqlite3.dll
  • %AppDataLocalLow%\{Random Characters}
  • %AppDataLocalLow%\{Random Characters}.zip
  • %AppDataLocalLow%\{Random Characters}\AccessibleHandler.dll
  • %AppDataLocalLow%\{Random Characters}\AccessibleMarshal.dll
  • %AppDataLocalLow%\{Random Characters}\IA2Marshal.dll
  • %AppDataLocalLow%\{Random Characters}\MapiProxy.dll
  • %AppDataLocalLow%\{Random Characters}\MapiProxy_InUse.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-file-l1-2-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-file-l2-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-handle-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-heap-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-interlocked-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-libraryloader-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-localization-l1-2-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-memory-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-namedpipe-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-processenvironment-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-processthreads-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-processthreads-l1-1-1.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-profile-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-rtlsupport-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-string-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-synch-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-synch-l1-2-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-sysinfo-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-timezone-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-core-util-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-conio-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-convert-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-environment-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-filesystem-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-heap-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-locale-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-math-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-multibyte-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-private-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-process-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-runtime-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-stdio-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-string-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-time-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\api-ms-win-crt-utility-l1-1-0.dll
  • %AppDataLocalLow%\{Random Characters}\breakpadinjector.dll
  • %AppDataLocalLow%\{Random Characters}\freebl3.dll
  • %AppDataLocalLow%\{Random Characters}\ldap60.dll
  • %AppDataLocalLow%\{Random Characters}\ldif60.dll
  • %AppDataLocalLow%\{Random Characters}\lgpllibs.dll
  • %AppDataLocalLow%\{Random Characters}\libEGL.dll
  • %AppDataLocalLow%\{Random Characters}\mozMapi32.dll
  • %AppDataLocalLow%\{Random Characters}\mozMapi32_InUse.dll
  • %AppDataLocalLow%\{Random Characters}\mozglue.dll
  • %AppDataLocalLow%\{Random Characters}\msvcp140.dll
  • %AppDataLocalLow%\{Random Characters}\nss3.dll
  • %AppDataLocalLow%\{Random Characters}\nssckbi.dll
  • %AppDataLocalLow%\{Random Characters}\nssdbm3.dll
  • %AppDataLocalLow%\{Random Characters}\prldap60.dll
  • %AppDataLocalLow%\{Random Characters}\qipcap.dll
  • %AppDataLocalLow%\{Random Characters}\softokn3.dll
  • %AppDataLocalLow%\{Random Characters}\ucrtbase.dll
  • %AppDataLocalLow%\{Random Characters}\vcruntime140.dll
  • %AppDataLocalLow%\{Random Characters}\{Random Characters}.zip

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.
  • %AppDataLocalLow%\{Random Characters}

Step 6

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.STOP.EI. 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:


Did this description help? Tell us how we did.