Ransom:Win32/Avaddon.PA!MTB(MICROSOFT); Win32/Filecoder.Avaddon.A trojan(NOD32);
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. It may be downloaded by other malware/grayware from remote sites.
It encrypts files found in specific folders. It drops files as ransom note. It avoids encrypting files with the following file extensions.
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.
It may be downloaded by the following malware/grayware from remote sites:
Installation
This Ransomware drops the following copies of itself into the affected system:
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following processes:
Autostart Technique
This Ransomware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
update = %Application Data%\{malware filename}.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
update = %Application Data%\{malware filename}.exe
Other System Modifications
This Ransomware adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0000
Owner = {HEX VALUES}
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0000
SessionHash = {HEX VALUES}
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0000
Sequence = {VALUE}
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0000
RegFiles0000 = {Target File Name}
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0000
RegFilesHash = {Hex Values}
It adds the following registry entries as part of its installation routine:
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
EnableLinkedConnections = 1
(Note: The default value data of the said registry entry is None.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
ConsentPromptBehaviorAdmin = 0
(Note: The default value data of the said registry entry is 5.)
It changes the desktop wallpaper by modifying the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Profile%\bckgrd.bmp
It sets the system's desktop wallpaper to the following image:
Process Termination
This Ransomware terminates the following services if found on the affected system:
It terminates the following processes if found running in the affected system's memory:
Other Details
This Ransomware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0000
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0001
HKEY_CURRENT_USER\Software\Microsoft\
RestartManager\Session0002
It connects to the following URL(s) to get the affected system's IP address:
It does the following:
It adds the following scheduled tasks:
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Ransomware Routine
This Ransomware encrypts files found in the following folders:
It avoids encrypting files with the following strings in their file name:
It avoids encrypting files with the following strings in their file path:
(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).. %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:
It drops the following file(s) as ransom note:
It avoids encrypting files with the following file extensions:
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:
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
Restart in Safe Mode
Step 5
Delete this registry key
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
Step 6
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 7
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
Step 8
Search and delete these files
Step 9
Deleting Scheduled Tasks
The following {Task Name} - {Task to be run} listed should be used in the steps identified below:
For Windows 2000, Windows XP, and Windows Server 2003:
For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
Step 10
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.AVADDON.YJAF-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 this Knowledge Base page for more information.
Step 11
Enabling Volume Shadow Service
Step 12
Enabling Windows Error Recovery
Step 13
Restore encrypted files from backup.