Ransom.Win32.YATRON.THCABAI

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 drops copies of itself in all removable and physical drives found in the system. It exploits software vulnerabilities to propagate to other computers across a network.

It encrypts files found in specific folders.

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 files:

• %Windows%\lan.dll - contains exploit configuration

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

Other System Modifications

This Ransomware modifies the following registry entries:

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = 0

Propagation

This Ransomware drops copies of itself into the following folders used in peer-to-peer (P2P) networks:

• %User Profile%\My Documents\Downloads
• %User Profile%\My Documents\My Shared Folder
• %User Profile%\My Documents\Shared
• %Application Data%\Ares\My Shared Folder
• %Desktop%\Downloads
• %Program Files%\Shareaza\Downloads
• %Program Files%\emule\incoming\
• %Program Files%\kazaa\my shared folder\
• %Program Files%\kazaa lite\my shared folder\
• %Program Files%\kazaa lite k++\my shared folder\
• %Program Files%\icq\shared folder\
• %Program Files%\grokster\my grokster\
• %Program Files%\bearshare\shared\
• %Program Files%\edonkey2000\incoming\
• %Program Files%\morpheus\my shared folder\
• %Program Files%\limewire\shared\
• %Program Files%\tesla\files\
• %Program Files%\winmx\shared

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista, 7, and 8.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista, 7, and 8.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), 7 (32-bit), and 8 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), 7 (64-bit), and 8 (64-bit).)

It drops copies of itself in all removable and physical drives found in the system.

It exploits the following software vulnerabilities to propagate to other computers across a network:

• EternalBlue
• DoublePulsar

Process Termination

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

• ProcessHacker
• apateDNS
• mbamgui
• mbam
• AntiLogger
• SbieCtrl
• SpyTheSpy
• SpeedGear
• wireshark
• IPBlocker
• cports
• procexp
• firefox
• vmware
• iexplore
• chrome
• dnSpy
• ILSpy

Other Details

This Ransomware encrypts files with the following extensions:

• .txt
• .doc
• .tgz
• .dox
• .amv
• .mpv
• .mtv
• .asp
• .aspx
• .html
• .xml
• .psd
• .pdf
• .exe
• .rv
• .rvx
• .ved
• .wm
• .wmv
• .TXT
• .JPG
• .rar
• .xwm
• .vwma
• .midi
• .fla
• .pdf
• .wma
• .ico
• .gif
• .GIF
• .ogg
• .mpg
• .icns
• .RAR
• .png
• .zip
• .BAT
• .Exe
• .c
• .exe
• .PNG
• .7z
• .7Z
• .tar
• .gz
• .h
• .docx
• .mp3
• .xls
• .xlsx
• .ppt
• .sql
• .wmv
• .mp4
• .mp3
• .dll
• .jar
• .pptx
• .odt
• .jpg
• .tar
• .gz
• .bmp
• .pbm
• .rt
• .3g2
• .3gp
• .7zip
• .aaf
• .zip
• .aep
• .aepx
• .aet
• .ai
• .aif
• .as
• .as3
• .asf
• .asp
• .asx
• .avi
• .bmp
• .exe
• .class
• .cpp
• .cs
• .csv
• .dat
• .db
• .dbf
• .doc
• .docb
• .docm
• .docx
• .dot
• .dotm
• .dotx
• .dwg
• .dxf
• .efx
• .eps
• .fla
• .flv
• .gif
• .h
• .idml
• .iff
• .indb
• .indd
• .indl
• .indt
• .inx
• .jar
• .java
• .jpeg
• .jpg
• .js
• .m3u
• .m3u8
• .m4u
• .max
• .mdb
• .mid
• .mkv
• .mov
• .mp3
• .mp4
• .mpa
• .mpeg
• .mpg
• .msg
• .pdb
• .pdf
• .php
• .plb
• .pmd
• .png
• .pot
• .potm
• .potx
• .ppam
• .ppj
• .pps
• .ppsm
• .ppsx
• .ppt
• .pptm
• .pptx
• .prel
• .prproj
• .ps
• .psd
• .py
• .ra
• .rar
• .raw
• .rb
• .rtf
• .sdf
• .sdf
• .ses
• .sldm
• .sldx
• .sql
• .svg
• .swf
• .tif
• .txt
• .vcf
• .vob
• .wav
• .wma
• .wmv
• .wpd
• .wps
• .xla
• .xlam
• .xll
• .xlm
• .xls
• .xlsb
• .xlsm
• .xlsx
• .xlt
• .xltm
• .xltx
• .xlw
• .xml
• .xqx
• .icxs
• .webdoc
• .pdd
• .xbplate
• .fpk
• .1st
• .y
• .eps
• .odt
• .png
• .pst
• .wp5
• .pfx
• .ptx
• .cr2
• .wmv
• .yal
• .epk
• .bsa
• .crt
• .dbf
• .wpd
• .cdr
• .forge
• .csv
• .zip
• .hkx
• .xlsx
• .yml
• .sum
• .odb
• .rgss3a
• .mdb
• .rim
• .mdbackup
• .wps
• .wmv
• .ff
• .wri
• .accdb
• .wma
• .upk
• .iwi
• .docm
• .wgz
• .xx
• .kf
• .xxx
• .3fr
• .der
• .p7b
• .pkpass
• .wire
• .ai
• .wotreplay
• .wpe
• .wdp
• .orf
• .slm
• .wp7
• .mrwref
• .litemod
• .doc
• .ncf
• .wmf
• .zip
• .sie
• .wpl
• .wcf
• .vcf
• .w3x
• .m2
• .zw
• .t13
• .w
• .dcr
• .odc
• .crw
• .vpk
• .x3d
• .zif
• .indd
• .xlsx
• .m3u
• .css
• .avi
• .x
• .esm
• .wm
• .wbm
• .fsh
• .wpb
• .xy
• .vtf
• .0
• .bkf
• .srw
• .3dm
• .xlsm
• .mef
• .ppt
• .jpg
• .mddata
• .sis
• .wn
• .mov
• .pef
• .psd
• .xpm
• .zdc
• .p12
• .raw
• .tax
• .sb
• .odm
• .r3d
• .rwl
• .das
• .z
• .itm
• .xdb
• .xwp
• .m4a
• .sav
• .hplg
• .bik
• .rb
• .hkdb
• .bc7
• .nrw
• .re4
• .pem
• .menu
• .zabw
• .xy3
• .big
• .pak
• .odp
• .mdf
• .rtf
• .lrf
• .rar
• .pptm
• .xdl
• .arch
• .sid
• .wsd
• .cer
• .xld
• .xls
• .ybk
• .syncdb
• .qic
• .dmp
• .asset
• .sidd
• .wsh
• .wp
• .xll
• .wpw
• .mcmeta
• xmind
• .erf
• .wpt
• .p7c
• .dng
• .ltx
• .d3dbsp
• .svg
• .bar
• .x3f
• .x3f
• .rofl
• .xlsm
• .dba
• .3ds
• .ysp
• .c
• .wpa
• .blob
• .ods
• .xyp
• .layout
• .snx
• .py
• .wav
• .mp4wallet
• .sql
• .wp4
• .wpg
• .xf
• .1
• .pptx
• .w
• .dazip
• .2bp
• .lbf
• .jpeg
• .wbz
• .xlgc
• .wbmp
• .t12
• .xmmap
• .jpe
• .ztmp
• .gdb
• .srf
• .xml
• .wdb
• .a
• .wmo
• .sr2
• .wbd
• .z3d
• .xls
• .itdb
• .hvpl
• .xlsb
• .wp6
• .docx
• .desc
• .ntl
• .bay
• .raf
• .wot
• .wmd
• .i
• .vfs0
• .apk
• .fos
• .map
• .zi
• .mpqge
• .tor
• .cfr
• .ibank
• .7z
• .itl
• .js
• .lvl
• .wb2
• .kdb
• .db0
• .qdf
• .wbc

It does the following:

• It encrypts files in fixed, removable and network drives.
• It executes the following command to terminate and delete itself:
  cmd.exe /C timeout 2 && Del /Q /F {malware directory}\{malware file name}
• It deletes the shadow volume copies, disables system recovery, and deletes backup catalog using the following command:
  cmd.exe /C vssadmin.exe delete shadows /all /quiet & wmic.exe shadowcopy delete & bcdedit /set {default} bootstatuspolicy ignoreallfailures & bcdedit /set {default} recoveryenabled no & wbadmin delete catalog -quiet
• It displays the following window after encryption:
  
• It gathers MAC address, computer name, OS version.

Ransomware Routine

This Ransomware encrypts files found in the following folders:

• %User Profile%\My Documents
• %User Profile%\My Pictures
• %All User Profile%\Desktop
• %Desktop%
• %User Profile%\My Music
• %Common Programs%
• %Application Data%
• %Favorites%
• %User Profile%\My Videos
• %Application Data%\Microsoft\Windows\Network Shortcuts
• %User Profile%\Recent
• %Start Menu%
• %User Startup%
• %User Profile%\Links
• %User Profile%\Contacts
• %User Profile%\Downloads
• %User Profile%\Searches
• %User Profile%\Videos

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista, 7, and 8.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista, 7, and 8.. %Common Programs% is the folder that contains common program groups for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs on Windows Vista, 7, and 8.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.. %Favorites% is the current user's Favorites folder, which is usually C:\Documents and Settings\{user name}\Favorites on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Favorites on Windows Vista, 7, and 8.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista, 7, and 8.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

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

• .Yatron

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

• %Desktop%\Read@My.txt