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Ransom.Win32.MERMAID.A

April 20, 2020
 Analysis by: Karen Ivy Titiwa
 ALIASES:

Ransom:Win32/Kizi!MSR (MICROSOFT); W32/Generic.NZK!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

Infection Channel:

Dropped by other malware, Downloaded from the Internet

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 adds certain registry entries to disable the Task Manager. This action prevents users from terminating the malware process, which can usually be done via the Task Manager.

It encrypts files with specific file extensions. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

681,472 bytes

File Type:

, EXE

Memory Resident:

Yes

Initial Samples Received Date:

23 Mar 2020

Payload:

Deletes files, Encrypts files

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 adds the following processes:

  • vssadmin delete shadows /all /quiet
  • wmic shadowcopy delete
  • bcdedit /set {default} bootstatuspolicy ignoreallfailures
  • bcdedit /set {default} recoveryenabled no
  • wbadmin delete catalog -quiet
  • wbadmin delete systemstatebackup
  • wbadmin delete systemstatebackup -keepversions:0
  • wbadmin delete backup

Other System Modifications

This Ransomware deletes the following files:

  • %System%\drivers\etc\host

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

It adds the following registry entries to disable the Task Manager:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .txt
  • .doc
  • .docx
  • .intex
  • .pdf
  • .zip
  • .rar
  • .onetoc
  • .css
  • .lnk
  • .xlsx
  • .ppt
  • .pptx
  • .odt
  • .jpg
  • .bmp
  • .ods
  • .png
  • .csv
  • .sql
  • .mdb
  • .sln
  • .php
  • .asp
  • .aspx
  • .odp
  • .html
  • .xml
  • .psd
  • .bk
  • .bat
  • .mp3
  • .mp4
  • .wav
  • .mdf
  • .ost
  • .wma
  • .avi
  • .divx
  • .mkv
  • .mpeg
  • .wmv
  • .mov
  • .ogg
  • .mid
  • .gif
  • .jpeg
  • .cs
  • .vb
  • .vbproj
  • .py
  • .asmx
  • .json
  • .mov
  • .jpe
  • .dib
  • .h
  • .cpp
  • .ico
  • .suo
  • .c
  • .vcxproj
  • .mml
  • .otp
  • .VDPROJ
  • .vcx\u0131tems
  • .py3
  • .pyc
  • .pyde
  • .resx
  • .pdb
  • .msg
  • .manifest
  • .settings
  • .dat
  • .jar
  • .ps1
  • .htm
  • .f3d
  • .myd
  • .dwg
  • .rtf
  • .apk
  • .iso
  • .7-zip
  • .ace
  • .arj
  • .bz2
  • .myi
  • .cab
  • .gzip
  • .lzh
  • .tar
  • .uue
  • .xz
  • .z
  • .001
  • .mpg
  • .odg
  • .core
  • .crproj
  • .pas
  • .db
  • .torrent
  • .csptoj
  • .config
  • .nef
  • .bin
  • .enigma
  • .log
  • .ovpn
  • .rc
  • .url
  • .csh
  • .cvproj
  • .odb
  • .dproj
  • .cfg
  • .csm
  • .7z
  • .3dm
  • .3ds
  • .3g2
  • .3gp
  • .602
  • .ost
  • .123
  • .ARC
  • .PAQ
  • .accdb
  • .aes
  • .ai
  • .asc
  • .asf
  • .backup
  • .bak
  • .brd
  • .cgm
  • .class
  • .cmd
  • .crt
  • .csr
  • .dbf
  • .dch
  • .otg
  • .der
  • .dif
  • .dip
  • .djvu
  • .docb
  • .docm
  • .dot
  • .dot
  • .dotm
  • .dotx
  • .dwg
  • .edb
  • .eml
  • .fla
  • .flv
  • .frm
  • .gpg
  • .gz
  • .hwp
  • .ibd
  • .java
  • .js
  • .sp
  • .key
  • .lay
  • .lay6
  • .ldf
  • .m3u
  • .m4u
  • .max
  • .ott
  • .p12
  • .pem
  • .pfx
  • .pl
  • .pot
  • .potm
  • .potx
  • .ppam
  • .pps
  • .ppsm
  • .ppsx
  • .pptm
  • .pst

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

  • the_ancients[MaMo_:)]

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

  • {Encrypted Directory}\Beni_Oku!!!.hta

It leaves text files that serve as ransom notes containing the following text:

  • DOSYALARIN SIFRELIDIR: Merhaba! Tüm belgeleriniz, fotograflariniz, veritabanlariniz ve diger önemli dosyalariniz SIFRELENDI! Gerçekten dosyalarini geri yüklemek istiyor musun? Eger istiyorsan, verilerinizin kilidini açmak için size özel olan desifre yazilimi satin almalisiniz! E-postamiza yazin - yardimail1@{BLOCKED}l.com eger 24 saat içinde cevap alamazsaniz, ek e-posta adresimize yazin - yardimail2@{BLOCKED}l.com Tüm dosyalarinizin sifresini nasil çözeceginize dair size tam bir talimat gönderecegiz. ========================================================================================================================================================== * NE YAPMALIYIM ??? ========================================================================================================================================================== Öncelikle dosyalariniz HASARLI DEGIL! Dosyalariniz M-M sifreleme algoritmasiyla degistirilmis ve sifrelenmistir. Bu degisiklik geri dönüsümlüdür. Dosyalarinizin sifresini çözmenin tek yolu size özel olan desifre aracini satin almaktir. Herhangi bir girisimde bulunmak dosyalarinizi dönülmez sekilde bozar ve üçüncü taraf yazilimiyla geri yüklemeye kalkismak dosyalariniz için ölümcül olacaktir. ========================================================================================================================================================== * PEKI DOSYALARIM ESKI HALINE DÖNECEKMI VE ÖDEMEYI NASIL YAPMALIYIM ??? ========================================================================================================================================================== Sifreyi çözmek için size özel olan desifre aracimizi satin almalisiniz, bunu zaten dedik. ve desifre aracinin fiyati 300 dolar, ödemeyi bitcoin yolu ile yapacaksiniz ve ödeme için bize ulasmalisiniz. Ödeme yapildiktan sonra size özel olan desifre aracini size e-posta yoluyla gönderecegiz. desifre aracini masaüstüne atip çalistirmak yeterlidir, sonra otomatik olarak tüm dosyalariniz eski haline dönecektir. ========================================================================================================================================================== * BEDAVA SIFRE ÇÖZME!!! ========================================================================================================================================================== Garanti olarak ücretsiz sifre çözme! Hizmetimize inanmiyorsaniz ve bir kanit görmek istiyorsaniz, bize test hakkinda soru sorabilirsiniz. sifre çözme için. Bize 2 adete kadar sifrelenmis dosya gönderirsiniz. Test için dosya göndermek için dosya paylasim servisini ve Win-Rar kullanin. Dosyalar 1 MB"den küçük olmalidir (arsivlenmemis) ve Dosyalar önemli olmamalidir! Bize veritabanlarini, yedekleri ve büyük excelleri göndermeyin. dosyalar vb. Sifreyi çözer ve sifresi çözülmüs dosyalarinizi bir kanit olarak geri göndeririz! ========================================================================================================================================================== * BITCOINS NASIL ALINIR ??? ========================================================================================================================================================== Bitcoin"lerin iki basit yolu var: Link1: https://{BLOCKED}o.me/en/support#/1_3 Link2: https://{BLOCKED}itcoins.net/guides/how-to-buy-bitcoins Bu linkler"deki bilgiyi dikkatlice okuyun, çünkü büyük miktarlarda bile satin almaniz gerekebilir. Not: Türkçe kaynak için çeviri kullanin. ========================================================================================================================================================== !!! DIKKAT !!! ========================================================================================================================================================== !!! 2 gün içinde ödeme yapmazsaniz sonsuza kadar dosyalarinizi kurtaramazsiniz. !!! Sifrelenmis dosyalari yeniden adlandirmayin. !!! Üçüncü taraf yazilimi kullanarak verilerinizin sifresini çözmeye çalismayin, bu kalici veri kaybina neden olabilir. !!! Dosyalarinizin üçüncü taraflarin yardimi ile çözülmesi, fiyatlarin artmasina neden olabilir ve sakin kimseye güvenmeyin köpeginize bile. ========================================================================================================================================================== * SIFRE ÇÖZME ARACI IÇIN GEREKEN ANAHAR ========================================================================================================================================================== Sakin bu anahtari degistirmeyin sifre çözme araci için bu anahtar gerekli eger dosyalariniz umrunuzda degilse kurcaliyabilirsiniz. ve unutmayinki bu anahtar AES-256 sifreleme sistemi ile sifrelenmistir. Anahtar1: {BLOCKED}VmFcLBBS3wBDh+F3uJJjLMtpih8miau0UCWIv+mVfgUQ5fJfZi1c3Ks9liFukF5+c376Y+vdqta6F64u6piB+CW1hXVA== ==========================================================================================================================================================

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.760.03

FIRST VSAPI PATTERN DATE:

23 Mar 2020

VSAPI OPR PATTERN File:

15.761.00

VSAPI OPR PATTERN Date:

24 Mar 2020

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.XXPE50FFF034

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

Identify and terminate files detected as Ransom.Win32.MERMAID.A

[ 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 5

Restart in Safe Mode

[ Learn More ]

Step 6

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\Policies\System
    • DisableTaskMgr = 1

Step 7

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.
  • {Encrypted Directory}\Beni_Oku!!!.hta

Step 8

Enabling Volume Shadow Service

  1. Run the command prompt (cmd.exe) as administrator.
  2. Enable Volume Shadow Service by typing the following command:
    net start vss

Step 9

Enabling Windows Error Recovery

  1. Run the command prompt (cmd.exe) as administrator.
  2. Enable Windows Error Recovery Screen on Startup by typing the following command:
    bcdedit /set {default} bootstatuspolicy displayallfailures

Step 10

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.MERMAID.A. 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 this Knowledge Base page for more information.

Step 11

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System%\drivers\etc\host

Step 12

Restore encrypted files from backup.

Step 13

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.MERMAID.A. 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:


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