Ransom.Win64.ASTROLOCKER.THCBDBA

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 executes then deletes itself afterward.

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 Temp%\{random 8 characters}.bat
• {Malware Path\Malware Name}.dll.log - log file where core count, total memory, OS Information, username, commandline, encrypted files, and malware sample's performance statistics are listed

(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).)

It adds the following processes:

• cmd /c ""%User Temp%\ {random 8 characters}.bat" "{Malware Path}\{Malware Name}.dll""

(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).)

It executes then deletes itself afterward.

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

• {32 Hex Characters generated from Volume Serial ID}

Other System Modifications

This Ransomware adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Classes\
.{Generated ID}\shell\Open
(Default) = explorer.exe RecoveryManual.html

Process Termination

This Ransomware terminates the following services if found on the affected system:

• database
• msexchange

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

• msftesql.exe
• sqlagent.exe
• sqlbrowser.exe
• sqlwriter.exe
• oracle.exe
• ocssd.exe
• dbsnmp.exe
• synctime.exe
• agntsvc.exe
• isqlplussvc.exe
• xfssvccon.exe
• sqlservr.exe
• mydesktopservice.exe
• ocautoupds.exe
• encsvc.exe
• firefoxconfig.exe
• tbirdconfig.exe
• mydesktopqos.exe
• ocomm.exe
• mysqld.exe
• mysqld-nt.exe
• mysqld-opt.exe
• dbeng50.exe
• sqbcoreservice.exe
• excel.exe
• infopath.exe
• msaccess.exe
• mspub.exe
• onenote.exe
• outlook.exe
• powerpnt.exe
• thebat.exe
• steam.exe
• thebat64.exe
• thunderbird.exe
• visio.exe
• winword.exe
• wordpad.exe
• QBW32.exe
• QBW64.exe
• ipython.exe
• wpython.exe
• python.exe
• dumpcap.exe
• procmon.exe
• procmon64.exe
• procexp.exe
• procexp64.exe

Information Theft

This Ransomware accepts the following parameters:

• /console - displays the following console window
  
• /nolog - disable the creation of the log file in the malware directory
• /scan: - specifies what drive type to encrypt
• /marker:{filename} - drops file in infected drive that serves as an infection marker
• /fullpd - encrypts %ProgramData%
• /nodel - disables self deletion after execution
• /nokill - disable process termination
• /fast:{value} - specifies which bytes to encrypt for faster file encryption
• /onlypath /path:{path} - only encrypts a specific path

Ransomware Routine

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

• RecoveryManual.html
• ReadManual.{Generated ID}

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

• \WindowsApps\
• \Microsoft\Windows\
• \Roaming\Microsoft\
• \Local\Microsoft\
• \LocalLow\Microsoft\
• \Local\Packages\
• \Windows Defender\
• \microsoft shared\
• \Google\Chrome\
• \Mozilla Firefox\
• \Mozilla\Firefox\
• \Internet Explorer\
• \MicrosoftEdge\
• \Tor Browser\
• \AppData\Local\Temp\

It avoids encrypting files found in the following folders:

• {Drive Letter}:\Windows\
• {Drive Letter}:\System Volume Information\
• {Drive Letter}:\$RECYCLE.BIN\
• {Drive Letter}:\SYSTEM.SAV
• {Drive Letter}:\WINNT
• {Drive Letter}:\$WINDOWS.~BT\
• {Drive Letter}:\Windows.old\
• {Drive Letter}:\PerfLog\
• {Drive Letter}:\Boot
• {Drive Letter}:\ProgramData\Packages\
• {Drive Letter}:\ProgramData\Microsoft\

It appends the following extension to the file name of the encrypted files:

• .ReadManual.{Generated ID}

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

• {Encrypted Folder}\RecoveryManual.html
  

It avoids encrypting files with the following file extensions:

• exe
• dll
• sys
• msi
• mui
• inf
• cat
• bat
• cmd
• ps1
• vbs
• ttf
• fon
• lnk