RANSOM_SCARAB.F

 Analysis by: Michael Jhon Ofiaza

 ALIASES:

Gen:Variant.Ransom.Scarab.3 (Bitdefender) , Ransom:Win32/Kitoles.A (Microsoft) , Trojan-Ransom.Win32.Purga.ed (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware


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 lowers the security setting of Internet Explorer.

It deletes itself after execution.

It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

193,024 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

17 Dec 2017

Payload:

Terminates processes

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 copies of itself into the affected system:

  • %Application Data%\sevnz.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It adds the following processes:

  • cmd.exe /c wbadmin DELETE SYSTEMSTATEBACKUP -keepVersions:0 -> deletes all the system state backups
  • cmd.exe /c wmic SHADOWCOPY DELETE -> deletes shadow copies
  • cmd.exe /c vssadmin Delete Shadows /All /Quiet -> deletes shadow copies
  • cmd.exe /c bcdedit /set {default} recoveryenabled No -> disable Windows Recovery option
  • cmd.exe /c bcdedit /set {default} bootstatuspolicy ignoreallfailures -> disable system's trigger to call the Error Recovery screen on startup

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

  • ILRTISo

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\RunOnce
ILRTISo = %Application Data%\sevnz.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ILRTISo = notepad.exe "%User Profile%\Инструкция по расшифровке.txt"

Process Termination

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

  • agntsvc.exe
  • isqlplussvc.exe
  • ncsvc.exe
  • msftesql.exe
  • sqlagent.exe
  • sqlbrowser.exe
  • sqlservr.exe
  • sqlserver.exe
  • sqlwriter.exe
  • oracle.exe
  • ocssd.exe
  • dbsnmp.exe
  • synctime.exe
  • mydesktopqos.exe
  • agntsvc.exeisqlplussvc.exe
  • xfssvccon.exe
  • mydesktopservice.exe
  • ocautoupds.exe
  • agntsvc.exeagntsvc.exe
  • agntsvc.exeencsvc.exe
  • firefoxconfig.exe
  • tbirdconfig.exe
  • ocomm.exe
  • mysqld.exe
  • mysqld-nt.exe
  • mysqld-opt.exe
  • dbeng50.exe
  • sqbcoreservice.exe

Web Browser Home Page and Search Page Modification

This Ransomware lowers the security setting of Internet Explorer.

Other Details

This Ransomware does the following:

  • The malware does not encrypt files located in %Program Files% and %Windows% except the following folders:
    • Microsoft\Exchange Server
    • Microsoft SQL Server
    • Firebird
    • MSSQL.1
    • Microsoft SQL Server Compact Edition
    • Adobe
    • Oracle
  • It avoids encrypting files with the following extensions:
    • exe
    • dll

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

It deletes itself after execution.

Ransomware Routine

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

  • .scarab

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

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.864.08

FIRST VSAPI PATTERN DATE:

25 Dec 2017

VSAPI OPR PATTERN File:

13.865.00

VSAPI OPR PATTERN Date:

26 Dec 2017

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

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 3

Identify and terminate files detected as RANSOM_SCARAB.F

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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\Microsoft\Windows\CurrentVersion\RunOnce
    • ILRTISo = %Application Data%\sevnz.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • ILRTISo = notepad.exe "%User Profile%\Инструкция по расшифровке.txt"

Step 5

Search and delete these files

[ 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.
  • Application Data%\sevnz.exe
  • {Folder of Encrypted Files}\Инструкция по расшифровке.TXT

Step 6

Reset Internet security settings

[ Learn More ]

Step 7

Scan your computer with your Trend Micro product to delete files detected as RANSOM_SCARAB.F. 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.

NOTES:

Enable Windows Recovery Option

1. Run cmd.exe as administrator

2. Type bcdedit /set {default} recoveryenabled Yes then press Enter.

3. Type bcdedit /set {default} bootstatuspolicy displayallfailures, then press Enter.

Additional notes for solution:

Depending on your operating system's (OS) setup, files needed in order to boot your OS may also be encrypted, making your OS unbootable.

In such situations, kindly do the following additional solution step:

Restore the system from backup or reinstall the operating system (OS).

The system may be made bootable by doing a system repair using a Windows installer disk.


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