Ransom.Win32.AVADDON.AA

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. 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.

Installation

This Ransomware drops the following files:

• %User Profile%\bcgrnimg.bmp

(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 adds the following processes:

• wmic.exe SHADOWCOPY /nointeractive
• wbadmin DELETE SYSTEMSTATEBACKUP
• wbadmin DELETE SYSTEMSTATEBACKUP -deleteOldest
• bcdedit.exe /set {default} recoveryenabled No
• bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
• vssadmin.exe Delete Shadows /All /Quiet

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

• Global\{UID}

Other System Modifications

This Ransomware modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
ConsentPromptBehaviorAdmin = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLinkedConnections = 1

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

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Profile%\bcrnimg.bmp

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

Process Termination

This Ransomware terminates the following processes if found running in the affected system's memory:

• sqlservr.exe
• sqlmangr.exe
• RAgui.exe
• QBCFMonitorService.exe
• supervise.exe
• fdhost.exe
• Culture.exe
• RTVscan.exe
• Defwatch.exe
• wxServerView.exe
• sqlbrowser.exe
• winword.exe
• GDscan.exe
• QBW32.exe
• QBDBMgr.exe
• qbupdate.exe
• axlbridge.exe
• 360se.exe
• 360doctor.exe
• QBIDPService.exe
• wxServer.exe
• httpd.exe
• fdlauncher.exe
• MsDtSrvr.exe
• tomcat6.exe
• java.exe
• wdswfsafe.exe

Information Theft

This Ransomware gathers the following data:

• Appended Random Extension
• RCID
• Disk Drive Properties (name, size, type)
• Computer Language
• Computer name
• Encryption Key Value

Other Details

This Ransomware does the following:

• Terminates itself if Windows Locale ID is equal to the following:
  • 1049 - Russian
  • 1115 - Cherokee (United States)
• Terminates itself if machine is set to the following keyboard layout language:
  • 1049 - Russian
  • 1157 - Yakut (Russia)
  • 1092 - Tatar
  • 1058 - Ukranian
• This ransomware encrypts all drives in the system (fixed, removable)

Ransomware Routine

This Ransomware encrypts files found in the following folders:

• %Program Files%\Microsoft SQL Server
• %Program Files%\Microsoft\Exchange Server

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It avoids encrypting files with the following strings in their file name:

• _readme.html
• bcrnimg.bmp

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

• Tor Browser
• MSO Cache
• AppData
• ProgramData
• Program Files
• Windows

It avoids encrypting files found in the following folders:

• %Windows%
• %Program Files%
• %System Root%\Users\All Users
• %Public%
• %User Temp%
• %User Profile%\AppData
• %ProgramData%

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Public% is the folder that serves as a repository of files or folders common to all users, which is usually C:\Users\Public in Windows Vista, 7, and 8.. %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).. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

It drops the following file(s) as ransom note:

• {Encrypted Directory}\{random characters}_readme.html
  

It avoids encrypting files with the following file extensions:

• .exe
• .bin
• .sys
• .ini
• .dll
• .lnk
• .dat
• .drv
• .rdp
• .prf
• .swp
• {appended extension string}