Ransom.MSIL.SCREENLOCKER.A
HEUR:Trojan.MSIL.Shutdowner.gen (Kaspersky), Trojan:Win32/Ymacco.AA27 (Microsoft)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Ransomware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
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
Modifies system registry, Terminates processes, Displays message/message boxes, Locks screen
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:
- {Malware Path}\Password.txt -> contains the password to be used for unlocking the system
- {Malware Path}\Restart.txt
- {Malware Path}\Timer.txt -> contains the time left before the system restarts
It adds the following processes:
- shutdown /r /t 1
- vssadmin delete shadows /all
- ipconfig /release
Other System Modifications
This Ransomware adds the following registry entries:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoClose = 1
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = {Malware Path}\{Malware Name}
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = 0
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
shutdownwithoutlogon = 0
(Note: The default value data of the said registry entry is 1.)
Process Termination
This Ransomware terminates the following processes if found running in the affected system's memory:
- Cmd
- Taskmgr
- Firefox
- Edge
- Telegram
- Explorer
- Chrome
Other Details
This Ransomware does the following:
- Gives the user 30 minutes to pay before the system restarts again and executes the following command:
- Bcdedit /delete {current}
- The password the malware is looking for is "P4YME0101"
- It shows the following window as a ransom note:
SOLUTION
9.850
16.192.05
15 Aug 2020
16.193.00
16 Aug 2020
Step 1
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 2
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 3
Identify and terminate files detected as Ransom.MSIL.SCREENLOCKER.A
- 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.
- 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.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
Delete this 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_LOCAL_MACHINE \Software\Microsoft\Windows NT\CurrentVersion\Winlogon
- Shell = {Malware Path}\{Malware Name}
- Shell = {Malware Path}\{Malware Name}
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- NoClose = 1
- NoClose = 1
Step 5
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_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System
- EnableLUA = 0
- EnableLUA = 0
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System
- shutdownwithoutlogon = 0
- shutdownwithoutlogon = 0
Step 6
Search and delete this file
{Malware Path}\Password.txt
{Malware Path}\Restart.txt
{Malware Path}\Timer.txt
Step 7
Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.SCREENLOCKER.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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