Modified by: Jemimah Mae Molina

ALIASES:

RDN/Ransom (McAfee); HEUR:Trojan.MSIL.DelShad.gen (Kaspersky)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, 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 encrypts files found in specific folders. It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 77,824 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 20 Aug 2019
Payload: Encrypts files, Deletes files, Displays message/message boxes

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 → deletes shadow copies
  • cipher /W:%System Root%:\ → wipes data from %System Root%
  • fsutil usn deletejournal /D %System Root% → delete an active USN change journal on %System Root%
  • shutdown -L → logs off the current user on machine

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

Other System Modifications

This Ransomware modifies the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %Desktop%\BACKGROUND.BMP

HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = 2

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
legalnoticecaption = Viagra yungthugger (V-0.1.31)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
legalnoticetext = {user name}, your files are encrypted. Look for README-VIAGRA-{8 random characters}.HTML in every folder, for instructions on how to get your files back.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
RegisteredOwner = {user name}, your files are encrypted. Look for README-VIAGRA-{8 random characters}.HTML in every folder, for instructions on how to get your files back.

It sets the system's desktop wallpaper to the following image:

Dropping Routine

This Ransomware drops the following files:

  • %Desktop%\BACKGROUND.BMP → used as wallpaper

(Note: %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).)

Other Details

This Ransomware encrypts files with the following extensions:

  • .txt
  • .doc
  • .jpg
  • .ogg
  • .jpeg
  • .tif
  • .tiff
  • .png
  • .docx
  • .docm
  • .xlsm
  • .xlsx
  • .pdf
  • .pptm
  • .pptx
  • .ppt
  • .xls
  • .xla
  • .dot
  • .dotm
  • .odb
  • .odf
  • .bmp
  • .odg
  • .htm
  • .html
  • .xml
  • .pfx
  • .bit
  • .pdf
  • .com
  • .css
  • .js
  • .vbs
  • .sln
  • .au3
  • .flac
  • .url
  • .ini
  • .cfg
  • .conf
  • .avi
  • .mp3
  • .m4a
  • .3gp
  • .vid
  • .vob
  • .asm
  • .webmoney
  • .sav
  • .nth
  • .java
  • .jar
  • .sis
  • .key
  • .$$$
  • .reg
  • .apk
  • .ncf
  • .navpath
  • .nfo
  • .nokogiri
  • .nrg
  • .nsh
  • .rtf
  • .nvram
  • .oa2
  • .oa3
  • .obj
  • .obt
  • .obx
  • .obz
  • .ocr
  • .odif
  • .odo
  • .oda
  • .odl
  • .osd
  • .osf
  • .ps1
  • .p01
  • .p10
  • .p12
  • .7z
  • .rar
  • .zip
  • .arj
  • .tar.gz
  • .tar
  • .pak
  • .pcd
  • .pdb
  • .pdc
  • .prc
  • .peb
  • .pef
  • .cad
  • .pkg
  • .ply
  • .ppx
  • .proofingtool
  • .ps
  • .pub
  • .pubx
  • .py
  • .pyc
  • .pys
  • .qbx
  • .r00
  • .rw
  • .rwlibrary
  • .so
  • .sam
  • .sh
  • .shtml
  • .xhtml
  • .smh
  • .opus
  • .sql
  • .sqlite1
  • .sqlite
  • .spb
  • .ssh
  • .struct
  • .suf
  • .ssx
  • .tex
  • .tdr
  • .jtd
  • .tga
  • .torrent
  • .tor
  • .tml
  • .lua
  • .tgz
  • .thm
  • .web
  • .wdb
  • .gif
  • .gadget
  • .erf
  • .wmv
  • .mov
  • .cdr
  • .qbm
  • .x11
  • .war
  • .eps
  • .bik
  • .jtt
  • .go
  • .602
  • .c
  • .cs
  • .h
  • .cpp
  • .hpp
  • .sln
  • .rdb
  • .cer
  • .mp2
  • .xhtml
  • .php
  • .mf
  • .xsl
  • .sheet
  • .sas7bdat
  • .djvu
  • .stone
  • .tga
  • .eml
  • .mmpz
  • .mmp
  • .bin
  • .3g2
  • .sql
  • .3dm
  • .wks
  • .wps
  • .mpa
  • .wpl
  • .deb
  • .elf
  • .dbg
  • .sav
  • .csv
  • .cgi
  • .bat
  • .wsf
  • .svg
  • .ico
  • .cfm
  • .rss
  • .class
  • .sh
  • .swift
  • .mkv
  • .sb
  • .pk3
  • .skb
  • .szs
  • .prz
  • .mpp
  • .spc
  • .myd
  • .ccp4
  • .eossa
  • .cdf
  • .ps1
  • .ps1xml
  • .p7b
  • .p7c
  • .gsm
  • .vgm
  • .bkp
  • .band
  • .hs
  • .gml
  • .e
  • .d
  • .xpl
  • .osr
  • .osu
  • .mcpack
  • .mctemplate
  • .lip
  • .3ds
  • .wad
  • .gba
  • .gbc
  • .fds
  • .maf
  • .jsp
  • .ihtml
  • .cps
  • .vb

It does the following:

  • It deletes the original files after encryption.
  • It modifies the volume label of encrypted drives to EnCiPhErEd-{8 random characters}.
  • It displays the following window upon execution:
  • It creates the following Windows pre-login message:

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • %System Root%\Users
  • %System Root%\Documents and Settings
  • %System Root%\xampp

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

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

  • .{base-64 encoded string}{4 random characters}

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

  • {Encrypted Directory}\README-VIAGRA-{8 random characters}.HTM

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.364.03
FIRST VSAPI PATTERN DATE: 13 Sep 2019
VSAPI OPR PATTERN File: 15.365.00
VSAPI OPR PATTERN Date: 14 Sep 2019

Step 1

Trend Micro products with the XGen technology detect this malware as

[ Learn More ]
 
  • Troj.Win32.TRX.XXPE50FFF031

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

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • Wallpaper = %Desktop%\BACKGROUND.BMP
  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • WallpaperStyle = 2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
    • legalnoticecaption = Viagra yungthugger (V-0.1.31)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
    • legalnoticetext = {user name}, your files are encrypted. Look for README-VIAGRA-{8 random characters}.HTML in every folder, for instructions on how to get your files back.
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • RegisteredOwner = {user name}, your files are encrypted. Look for README-VIAGRA-{8 random characters}.HTML in every folder, for instructions on how to get your files back.

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.  
  • %Desktop%\BACKGROUND.BMP
  • {Encrypted Directory}\README-VIAGRA-{8 random characters}.HTM

Step 6

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.VIGRA.THIODAIA. 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 7

Restore encrypted files from backup.

Step 8

Reset your Desktop properties

[ Learn More ]

NOTES:

  • Enabling Volume Shadow Service
    • Run the command prompt (cmd.exe) as administrator.
    • Enable volume shadow service using the following command:
      net start


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