arrow_back
search
close

Ransom.Win32.BALACLAVA.A

March 25, 2020
 Analysis by: Emilio Marcel Garcia
 ALIASES:

Ransom:Win32/Filecoder!MSR (MICROSOFT); Trojan-Ransom.Win32.Gen.vuu (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

67,584 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

26 Feb 2020

Payload:

Displays message/message boxes, Encrypts files

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:

  • %Public%\{random characters} -> encrypted ransom note
  • %User Temp%\TotalFiles.txt -> contains the total count of encrypted files

(Note: %Public% is the folder that serves as a repository of files or folders common to all users, which is usually C:\Users\Public in Windows Vista, 7, and 8.. %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).)

Other Details

This Ransomware deletes itself after execution.

Ransomware Routine

This Ransomware avoids encrypting files with the following strings in their file path:

  • AVG
  • Avast
  • Avira
  • COMODO
  • Chrome
  • Common Files
  • Common7
  • Dr. Web
  • ESET
  • Firefox
  • HOW_TO_RECOVERY_FILES.txt
  • Internet Explorer
  • Kaspersky Lab
  • McAfee
  • Microsoft
  • Microsoft Help
  • Microsoft SDKs
  • Microsoft Shared
  • Microsoft VS Code
  • Microsoft Visual Studio
  • Microsoft .NET
  • Movie Maker
  • Mozilla Firefox
  • NVIDIA Corporation
  • Opera
  • Outlook Express
  • ProgramData
  • Spytech software
  • Symantec
  • Symantec_Client_Security
  • sysconfig
  • System Volume Information
  • TEMP
  • Temp
  • Windows
  • Windows App Certification Kit
  • Windows Defender
  • Windows Kits
  • Windows Mail
  • Windows Media Player
  • Windows Multimedia Platform
  • Windows NT
  • Windows Phone Kits
  • Windows Phone Silverlight Kits
  • Windows Photo Viewer
  • Windows Portable Devices
  • Windows Sidebar
  • Windows Powershell
  • Wsus
  • YandexBrowser

It appends the following extension to the file name of the encrypted files:

  • .{BLOCKED}glanville_data@{BLOCKED}l.com

It leaves text files that serve as ransom notes containing the following text:

  • {Encrypted folder}\HOW_TO_RECOVERY_FILES.txt
  • C:\$Recycle.Bin\{user SID}\HOW_TO_RECOVERY_FILES.txt
  • C:\$Recycle.Bin\HOW_TO_RECOVERY_FILES.txt
  • %Desktop%\HOW_TO_RECOVERY_FILES.txt

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.724.03

FIRST VSAPI PATTERN DATE:

05 Mar 2020

VSAPI OPR PATTERN File:

15.725.00

VSAPI OPR PATTERN Date:

06 Mar 2020

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.XXPE50FFF034

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

Identify and terminate files detected as Ransom.Win32.BALACLAVA.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 5

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.
  • %Public%\{random characters}
  • %User Temp%\TotalFiles.txt
  • C:\$Recycle.Bin\{user SID}\HOW_TO_RECOVERY_FILES.txt
  • C:\$Recycle.Bin\HOW_TO_RECOVERY_FILES.txt
  • %Desktop%\HOW_TO_RECOVERY_FILES.txt
  • {Encrypted folder}\HOW_TO_RECOVERY_FILES.txt

Step 6

Scan your computer with your Trend Micro product to clean files detected as Ransom.Win32.BALACLAVA.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:

Step 7

Restore encrypted files from backup.


Did this description help? Tell us how we did.