Ransom.MSIL.RANTESUTO.THFBFBC
VHO:Trojan-Ransom.MSIL.Agent.gen (KASPERSKY)
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
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 encrypts files found in specific folders.
TECHNICAL DETAILS
438,784 bytes
EXE
No
26 Jun 2023
Encrypts files, Displays graphics/image
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 adds the following processes:
- cmd.exe "/k REG add HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /t REG_DWORD /d 0 /f && exit"
- "runas.exe" /user:Administrator "cmd /K start notepad"
Other System Modifications
This Ransomware modifies the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\xz.bmp
It sets the system's desktop wallpaper to the following image:
- %User Temp%\xz.bmp
Other Details
This Ransomware does the following:
- It displays the following GUI showing an option to Encrypt or to Decrypt
- It decrypts encrypted files found in the following specific folders in C drive:
- %Desktop%
- %User Profile%\Pictures
Ransomware Routine
This Ransomware encrypts files found in the following folders:
- The following specific folders in C drive:
- %Desktop%
- %User Profile%\Pictures
- %User Profile%\Documents
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It appends the following extension to the file name of the encrypted files:
- .TEST
SOLUTION
9.800
18.532.04
26 Jun 2023
18.533.00
27 Jun 2023
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.XXPE50FFF069
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
Restore this modified registry value
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\Control Panel\Desktop
- Wallpaper = %User Temp%\xz.bmp
- Wallpaper = %User Temp%\xz.bmp
Step 5
Search and delete this file
- %User Temp%\xz.bmp
Step 6
Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.RANTESUTO.THFBFBC. 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.
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