arrow_back
search
close

Ransom.Win32.MZREVENGE.A

January 09, 2020
 Analysis by: Earle Maui Earnshaw
 ALIASES:

HEUR:Trojan-Ransom.Win32.CryFile.gen (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, 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 encrypts files with specific file extensions. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

2,701,824 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

18 Dec 2019

Payload:

Encrypts files, Modifies system registry, Displays graphics/image

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} bootstatus policy ignoreallfailures
  • bcdedit /set {default} recoveryenabled no
  • wbadmin delete catalog - quiet

Other System Modifications

This Ransomware adds the following registry keys:

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

Other Details

This Ransomware does the following:

  • Encrypts drives A: to Z:.

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
  • .vcxitems
  • .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
  • .raw
  • .rb
  • .sch
  • .sh
  • .sldm
  • .sldx
  • .slk
  • .snt
  • .sqlite3
  • .sqlitedb
  • .stc
  • .std
  • .sti
  • .stw
  • .svg
  • .swf
  • .sxc
  • .sxd
  • .sxi
  • .sxm
  • .sxw
  • .tbk
  • .tgz
  • .tif
  • .tiff
  • .uop
  • .uot
  • .vbs
  • .vcd
  • .vdi
  • .vmdk
  • .vbe
  • .vmx
  • .vob
  • .vsd
  • .vsdx
  • .wb2
  • .wk1
  • .wks
  • .xlc
  • .xlm
  • .xlsb
  • .xlsm
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .mkv
  • .img
  • .vbox

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

  • .MZ173801

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

  • {Encrypted Directory}\Read_ME_PLS.txt

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

  SOLUTION

Minimum Scan Engine:

9.850

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.XXPE50FFF033

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

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 4

Restart in Safe Mode

[ Learn More ]

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.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • DisableTaskMgr = "1"

Step 6

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}\Read_ME_PLS.txt

Step 7

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 8

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 9

Enabling Startup Repair

  1. Run the command prompt (cmd.exe) as administrator.
  2. Enable Startup Repair by typing the following command:
    /bcedit /set {default} recoveryenabled Yes

Step 10

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.MZREVENGE.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 encrypted files from backup.


Did this description help? Tell us how we did.