Analysis by: Jay Bradley Nebre
ALIASES:

Trojan.Win32.Fsysna.faav(Kaspersky); Ransom:Win32/Shade.B!bit(Microsoft)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This ransomware comes from a high volume spam campaign that aims to deliver this to as many users possible.

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 connects to certain websites to send and receive information.

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

  TECHNICAL DETAILS

File Size: 1,254,664 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 26 Feb 2019
Payload: Connects to URLs/IPs, Sets desktop paper to a specific image, Drops 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 drops the following copies of itself into the affected system:

  • %All Users Profile%\Windows\csrss.exe

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

It drops the following files:

  • %User Temp%\{Random Folder Name}\cached-certs
  • %User Temp%\{Random Folder Name}\cached-microdesc-consensus
  • %User Temp%\{Random Folder Name}\cached-microdescs.new
  • %User Temp%\{Random Folder Name}\lock
  • %User Temp%\{Random Folder Name}\state
  • %User Temp%\{Random Folder Name}\unverified-microdesc-consensus

(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).)

It adds the following processes:

  • %System%\vssadmin.exe List Shadows
  • %System%\vssadmin.exe Delete Shadows /All /Quiet
  • %System%\cmd.exe chcp

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

Autostart Technique

This Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Client Server Runtime Subsystem = "%All Users Profile%\Windows\csrss.exe"

Other System Modifications

This Ransomware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
xVersion = 4.0.0.1

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
xmail = {Number}

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
xmode = {Number}

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
xstate = {Number}

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
xcnt = {Number}

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
shst = {Number}

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
sh2 = {Base64 Encoded Data}

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
shsnt = {Number}

HKEY_LOCAL_MACHINE\SOFTWARE\System32\
Configuration
xi = D7C7911B1FBBD763C92B

It changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %Application Data%\{Random Filename}.bmp

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

  • %Application Data%\{Random Filename}.bmp

Information Theft

This Ransomware gathers the following data:

  • Computer name
  • User name
  • IP address
  • Computer domain
  • List of logical drives
  • Windows version
  • List of installed software

Other Details

This Ransomware connects to the following URL(s) to get the affected system's IP address:

  • http://{BLOCKED}ddress.com/
  • http://{BLOCKED}yip.net/

It connects to the following website to send and receive information:

  • http://{BLOCKED}p2xzclh6fd.onion/{Path}
    where {Path} can be any of the following:
    • reg.php
    • prog.php
    • err.php
    • cmd.php
    • sys.php
    • shd.php
    • mail.php

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .1cd
  • .3ds
  • .3fr
  • .3g2
  • .3gp
  • .7z
  • .accda
  • .accdb
  • .accdc
  • .accde
  • .accdt
  • .accdw
  • .adb
  • .adp
  • .ai
  • .ai3
  • .ai4
  • .ai5
  • .ai6
  • .ai7
  • .ai8
  • .anim
  • .arw
  • .as
  • .asa
  • .asc
  • .ascx
  • .asm
  • .asmx
  • .asp
  • .aspx
  • .asr
  • .asx
  • .avi
  • .avs
  • .backup
  • .bak
  • .bay
  • .bd
  • .bin
  • .bmp
  • .bz2
  • .c
  • .cbf
  • .cdr
  • .cer
  • .cf
  • .cfc
  • .cfm
  • .cfml
  • .cfu
  • .chm
  • .cin
  • .class
  • .clx
  • .config
  • .cpp
  • .cr2
  • .crt
  • .crw
  • .crypted
  • .cs
  • .css
  • .csv
  • .cub
  • .dae
  • .dat
  • .db
  • .dbf
  • .dbx
  • .dc3
  • .dcm
  • .dcr
  • .der
  • .dib
  • .dic
  • .dif
  • .divx
  • .djvu
  • .dmp
  • .dng
  • .doc
  • .docm
  • .docx
  • .dot
  • .dotm
  • .dotx
  • .dpx
  • .dqy
  • .dsn
  • .dt
  • .dtd
  • .dwg
  • .dwt
  • .dx
  • .dxf
  • .edml
  • .efd
  • .elf
  • .emf
  • .eml
  • .emz
  • .epf
  • .eps
  • .epsf
  • .epsp
  • .erf
  • .exr
  • .f4v
  • .fbk
  • .fdb
  • .fido
  • .fld
  • .flm
  • .flv
  • .frm
  • .fxg
  • .geo
  • .gif
  • .grs
  • .gz
  • .h
  • .hdr
  • .hpp
  • .hta
  • .htc
  • .htm
  • .html
  • .icb
  • .ics
  • .iff
  • .inc
  • .indd
  • .ini
  • .iqy
  • .j2c
  • .j2k
  • .java
  • .jp2
  • .jpc
  • .jpe
  • .jpeg
  • .jpf
  • .jpg
  • .jpx
  • .js
  • .jsf
  • .json
  • .jsp
  • .kdc
  • .kmz
  • .kwm
  • .lasso
  • .lbi
  • .lgf
  • .lgp
  • .log
  • .lst
  • .m1v
  • .m4a
  • .m4v
  • .max
  • .md
  • .mda
  • .mdb
  • .mde
  • .mdf
  • .mdw
  • .mef
  • .mft
  • .mfw
  • .mht
  • .mhtml
  • .mka
  • .mkidx
  • .mkv
  • .mos
  • .mov
  • .mp3
  • .mp4
  • .mpeg
  • .mpg
  • .mpv
  • .mrw
  • .msg
  • .mtr
  • .mxl
  • .myd
  • .myi
  • .nef
  • .nrw
  • .obj
  • .odb
  • .odc
  • .odm
  • .odp
  • .ods
  • .oft
  • .one
  • .onepkg
  • .onetoc2
  • .opt
  • .oqy
  • .orf
  • .p12
  • .p7b
  • .p7c
  • .pam
  • .pbm
  • .pct
  • .pcx
  • .pdd
  • .pdf
  • .pdp
  • .pef
  • .pem
  • .pff
  • .pfm
  • .pfx
  • .pgm
  • .php
  • .php3
  • .php4
  • .php5
  • .phtml
  • .pict
  • .pl
  • .pls
  • .pm
  • .png
  • .pnm
  • .pot
  • .potm
  • .potx
  • .ppa
  • .ppam
  • .ppm
  • .pps
  • .ppsm
  • .ppt
  • .pptm
  • .pptx
  • .prn
  • .ps
  • .psb
  • .psd
  • .pst
  • .ptx
  • .pub
  • .pwm
  • .pxr
  • .py
  • .qt
  • .r3d
  • .raf
  • .rar
  • .raw
  • .rdf
  • .rgbe
  • .rle
  • .rqy
  • .rss
  • .rtf
  • .rw2
  • .rwl
  • .safe
  • .sct
  • .sdpx
  • .shtm
  • .shtml
  • .slk
  • .sln
  • .sql
  • .sr2
  • .srf
  • .srw
  • .ssi
  • .st
  • .stm
  • .svg
  • .svgz
  • .swf
  • .tab
  • .tar
  • .tbb
  • .tbi
  • .tbk
  • .tdi
  • .tga
  • .thmx
  • .tib
  • .tif
  • .tiff
  • .tld
  • .torrent
  • .tpl
  • .txt
  • .u3d
  • .udl
  • .uxdc
  • .vault
  • .vb
  • .vbk
  • .vbm
  • .vbs
  • .vcs
  • .vda
  • .vdr
  • .vdw
  • .vdx
  • .vhd
  • .vib
  • .vrp
  • .vsd
  • .vss
  • .vst
  • .vsw
  • .vsx
  • .vtm
  • .vtml
  • .vtx
  • .wav
  • .wb2
  • .wbm
  • .wbmp
  • .wim
  • .wmf
  • .wml
  • .wmv
  • .wpd
  • .wps
  • .x3f
  • .xl
  • .xla
  • .xlam
  • .xlk
  • .xlm
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .xml
  • .xps
  • .xsd
  • .xsf
  • .xsl
  • .xslt
  • .xsn
  • .xtp
  • .xtp2
  • .xyze
  • .xz
  • .zip

It renames encrypted files using the following names:

  • {Random Filename}.{ID}.crypted000007

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

  • {Drive Letter}:\README{1-10}.txt
  • %Desktop%\README{1-10}.txt

(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).)

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

  • README{1-10}.txt

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.838.03
FIRST VSAPI PATTERN DATE: 27 Feb 2019
VSAPI OPR PATTERN File: 14.839.00
VSAPI OPR PATTERN Date: 28 Feb 2019

Step 1

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 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

Restart in Safe Mode

[ Learn More ]

Step 4

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_LOCAL_MACHINE\SOFTWARE\System32
    • Configuration

Step 5

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_LOCAL_MACHINE\SOFTWARE\System32\Configuration
    • xVersion = 4.0.0.1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\System32\Configuration
    • xmail = {Number}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\System32\Configuration
    • xmode = {Number}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\System32\Configuration
    • xstate = {Number}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\System32\Configuration
    • xcnt = {Number}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\System32\Configuration
    • shst = {Number}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\System32\Configuration
    • sh2 = {Base64 Encoded Data}

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.
  • %All Users Profile%\Windows\csrss.exe
  • %User Temp%\{Random Folder Name}\cached-certs
  • %User Temp%\{Random Folder Name}\cached-microdesc-consensus
  • %User Temp%\{Random Folder Name}\cached-microdescs.new
  • %User Temp%\{Random Folder Name}\lock
  • %User Temp%\{Random Folder Name}\state
  • %User Temp%\{Random Folder Name}\unverified-microdesc-consensus
  • %Application Data%\{Random Filename}.bmp
  • {Drive Letter}:\README{1-10}.txt
  • %Desktop%\README{1-10}.txt

Step 7

Reset your Desktop properties

[ Learn More ]

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.SHADE.THBBFAI. 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 9

Restore encrypted files from backup.


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