Ransom.Win32.LOCKCRYPT.EKNAK.go

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 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:

• %System Root%\Users\Public\.lock
• %Desktop%\Readme.html
• {Malware directory}\files.txt

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

• %System%\cmd.exe /c vssadmin delete shadows /all /quiet
• %System%\wevtutil.exe cl system
• %System%\wevtutil.exe cl security

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other System Modifications

This Ransomware deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Terminal Server Client
Default = " "

HKEY_CURRENT_USER\Software\Microsoft\
Terminal Server Client
Servers = " "

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer
WordWheelQuery = " "

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer
TypedPaths = " "

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer
RunMRU = " "

Process Termination

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

• mysqld-opt.exe
• dbeng50.exe
• msftestsql.exe
• agentsvc.exe
• ocomm.exe
• ocssd.exe
• firefoxconfig.exe
• excel.exe
• mysql-nt.exe
• onenote.exe
• outlook.exe
• tnslsnr.exe
• oracle.exe
• mysqld.exe
• mydesktopservice.exe
• thebat.exe
• powerpnt.exe
• visio.exe
• infopath.exe
• dbsnmp.exe
• steam.exe
• winword.exe
• wordpad.exe
• mspub.exe
• synctime.exe
• sqbcoreservice.exe
• sqlbrowser.exe
• thunderbird.exe
• mysqld-nt.exe
• tnslsnr.exe
• mysqld.exe
• sqlwriter.exe
• sqlservr.exe
• sqlagent.exe
• msftesql.exe
• encsvc.exe
• isqlplussvc.exe
• tbirdconfig.exe
• xfssvccon.exe

Ransomware Routine

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

• $recycle.bin
• all users
• appdata
• application data
• boot
• config.msi
• default
• msocache
• perflogs
• program files
• program files (x86)
• programdata
• public
• system volume information
• windows
• windows.old

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

• {Original Filename & file extension}.[Readme.html on Desktop}

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

• %Desktop%\Readme.html
  

It avoids encrypting files with the following file extensions:

• inf
• bat
• cab
• cmd
• com
• cpl
• cur
• dll
• drv
• exe
• hlp
• hta
• icl
• ico
• idx
• ini
• lnk
• msi
• ocx
• spl
• sys
• [Readme.html on Desktop]