Analysis by: Joshua John Bantayan

ALIASES:

Ransom:MSIL/NoCry.AS!MTB (MICROSOFT); Trojan-Ransom.FileCrypter (IKARUS)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Canal de infección 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 connects to a website to send and receive information.

It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

Tamaño del archivo 215,552 bytes
Tipo de archivo EXE
Residente en memoria Yes
Fecha de recepción de las muestras iniciales 03 May 2021
Carga útil Connects to URLs/IPs, 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 copies of itself into the affected system:

  • %User Startup%\{Mutex Name}.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

It drops the following files:

  • %User Temp%\Cry.img

(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).)

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

  • rGoB8VnbP6W42hW5

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
F\0
Runcount.cry = {Random Characters}

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
G\0
Runcount.cry = {Random Characters}

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
H\0
Runcount.cry = {Random number}

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
M\0
Runcount.cry = {Random number}

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
S\0
Runcount.cry = {Random number}

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
P\0
Runcount.cry = {Random number}

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
X\0
Runcount.cry = {Random number}

It changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\Cry.img

It sets the system's desktop wallpaper to the following image:

Backdoor Routine

This Ransomware connects to the following websites to send and receive information:

  • https://niddle-noddle-eyes.{BLOCKED}hostapp.com/log.php

Other Details

This Ransomware adds the following registry keys:

HKEY_CURRENT_USER\Software\VB and VBA Program Settings

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
F

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
F\0

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
G

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
G\0

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
H

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
H\0

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
M

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
M\0

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
S

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
S\0

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
P

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
P\0

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
X

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
X\0

It does the following:

  • It deletes system restore points.
  • It searches for files to encrypt in fixed drives, removable drives.
  • It displays the following window as a ransom note:

Ransomware Routine

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

  • Bin
  • indows
  • tings
  • System Volume Information
  • cache
  • very
  • rogram Files (x86)
  • rogram Files
  • boot
  • efi
  • .old
  • %System Root%

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

It avoids encrypting files with the following file extensions:

  • .cry

  SOLUTION

Motor de exploración mínimo 9.800
Primer archivo de patrones de VSAPI 16.750.04
Primera fecha de publicación de patrones de VSAPI 30 May 2021
Versión de patrones OPR de VSAPI 16.751.00
Fecha de publicación de patrones OPR de VSAPI 31 May 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.XXPE50FFF044

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.MSIL.NOCRY.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

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\VB and VBA Program Settings\F\0
    • Runcount.cry = {Random Characters}
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\G\0
    • Runcount.cry = {Random Characters}
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\H\0
    • Runcount.cry = {Random number}
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\M\0
    • Runcount.cry = {Random number}
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\S\0
    • Runcount.cry = {Random number}
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\P\0
    • Runcount.cry = {Random number}
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\X\0
    • Runcount.cry = {Random number}

Step 6

Delete this registry key

[ 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
    • VB and VBA Program Settings
  • In HKEY_CURRENT_USER\Software\VB and VBA Program SettingsF
    • 0
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
    • F
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\G
    • 0
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
    • G
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\H
    • 0
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
    • H
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\M
    • 0
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
    • M
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\S
    • 0
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
    • S
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\P
    • 0
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
    • P
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\X
    • 0
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings
    • X

Step 7

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 Startup%\{Mutex Name}.exe
  • %User Temp%\Cry.img

Step 8

Reset your Desktop properties

[ Learn More ]

Step 9

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.NOCRY.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 10

Restore encrypted files from backup.


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