Trojan-Ransom.FileCrypter (IKARUS)
Windows
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.
As of this writing, the said sites are inaccessible.
It drops files as ransom note.
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:
It adds the following processes:
It creates the following folders:
(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).)
Autostart Technique
This Ransomware drops the following file(s) in the Windows Common Startup folder to enable its automatic execution at every system startup:
(Note: %Common Startup% is the startup folder for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)
Other System Modifications
This Ransomware adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Keyboard Layout
Scancode Map = {Hex Values}
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
PromptOnSecureDesktop = 0
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
ConsentPromptBehaviorAdmin = 0
(Note: The default value data of the said registry entry is 5.)
HKEY_CURRENT_USER\Control Panel\Mouse
SwapMouseButtons = 1
(Note: The default value data of the said registry entry is 0.)
It uses Windows Management Instrumentation (WMI) to delete volume shadow copies:
Process Termination
This Ransomware terminates the following processes if found running in the affected system's memory:
Download Routine
This Ransomware connects to the following URL(s) to download its component file(s):
As of this writing, the said sites are inaccessible.
Other Details
This Ransomware does the following:
It adds the following scheduled tasks:
(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).)
Ransomware Routine
This Ransomware appends the following extension to the file name of the encrypted files:
It drops the following file(s) as ransom note:
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
Restart in Safe Mode
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.
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.
Step 6
Delete the Scheduled Tasks added by this malware/grayware
To delete the added Scheduled Task file:
For Windows 7, Windows Server 2008 (R2), Windows 8, Windows 8.1, Windows 10, and Windows Server 2012 (R2):
Step 7
Search and delete these folders
Step 8
Search and delete this file
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.HUMBLE.THBAGBB. 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 this Knowledge Base page for more information.