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RANSOM_WALTRIX.A

April 27, 2016
 Analysis by: Francis Xavier Antazo
 ALIASES:

Trojan:Win32/Dynamer!ac (Micorosft); a variant of Win32/Kryptik.EUSG (ESET); Trojan.Cryptolocker.AN (Symantec); Ransom.CryptXXX (Malwarebytes);

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet


This Trojan 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.

  TECHNICAL DETAILS

File Size:

450,560 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

18 Apr 2016

Payload:

Connects to URLs/IPs, Steals information

Arrival Details

This Trojan 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 Trojan drops the following non-malicious files:

  • %All Users Profile%\Application Data\{random file name}.dat

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Pattern = ""

(Note: The default value data of the said registry entry is "{User Preference}".)

HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"

(Note: The default value data of the said registry entry is "{User Preference}".)

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%System Root%\Python{version}\tcl\tk{version}\demos\images\de_crypt_readme.bmp"

(Note: The default value data of the said registry entry is "{User Preference}".)

Process Termination

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

  • bitcoin-qt.exe
  • litecoin-qt.exe
  • msigna.exe
  • Copay.exe

Other Details

This Trojan connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.42.68

It encrypts files with the following extensions:

  • .3dm
  • .3ds
  • .3g2
  • .3gp
  • .7z
  • .accdb
  • .aes
  • .ai
  • .aif
  • .apk
  • .app
  • .arc
  • .asc
  • .asf
  • .asm
  • .asp
  • .aspx
  • .asx
  • .avi
  • .bat
  • .bmp
  • .brd
  • .bz2
  • .c
  • .cer
  • .cfg
  • .cfm
  • .cgi
  • .cgm
  • .class
  • .cmd
  • .cpp
  • .crt
  • .cs
  • .csr
  • .css
  • .csv
  • .cue
  • .db
  • .dbf
  • .dch
  • .dcu
  • .dds
  • .dif
  • .dip
  • .djv
  • .djvu
  • .doc
  • .docb
  • .docm
  • .docx
  • .dot
  • .dotm
  • .dotx
  • .dtd
  • .dwg
  • .dxf
  • .eml
  • .eps
  • .fdb
  • .fla
  • .flv
  • .frm
  • .gadget
  • .gbk
  • .gbr
  • .ged
  • .gif
  • .gpg
  • .gpx
  • .gz
  • .h
  • .htm
  • .html
  • .hwp
  • .ibd
  • .ibooks
  • .iff
  • .indd
  • .jar
  • .java
  • .jks
  • .jpg
  • .js
  • .jsp
  • .key
  • .kml
  • .kmz
  • .lay
  • .lay6
  • .ldf
  • .lua
  • .m
  • .m3u
  • .m4a
  • .m4v
  • .max
  • .mdb
  • .mdf
  • .mfd
  • .mid
  • .mkv
  • .mml
  • .mov
  • .mp3
  • .mp4
  • .mpa
  • .mpg
  • .ms11
  • .msi
  • .myd
  • .myi
  • .nef
  • .note
  • .obj
  • .odb
  • .odg
  • .odp
  • .ods
  • .odt
  • .otg
  • .otp
  • .ots
  • .ott
  • .p12
  • .pages
  • .paq
  • .pas
  • .pct
  • .pdb
  • .pdf
  • .pem
  • .php
  • .pif
  • .pl
  • .plugin
  • .png
  • .pot
  • .potm
  • .potx
  • .ppam
  • .pps
  • .ppsm
  • .ppsx
  • .ppt
  • .pptm
  • .pptx
  • .prf
  • .priv
  • .private
  • .ps
  • .psd
  • .pspimage
  • .py
  • .qcow2
  • .ra
  • .rar
  • .raw
  • .rm
  • .rss
  • .rtf
  • .sch
  • .sdf
  • .sh
  • .sitx
  • .sldx
  • .slk
  • .sln
  • .sql
  • .sqlite3
  • .sqlitedb
  • .srt
  • .stc
  • .std
  • .sti
  • .stw
  • .svg
  • .swf
  • .sxc
  • .sxd
  • .sxi
  • .sxm
  • .sxw
  • .tar
  • .tbk
  • .tex
  • .tga
  • .tgz
  • .thm
  • .tif
  • .tiff
  • .tlb
  • .tmp
  • .txt
  • .uop
  • .uot
  • .vb
  • .vbs
  • .vcf
  • .vcxproj
  • .vdi
  • .vmdk
  • .vmx
  • .vob
  • .wav
  • .wks
  • .wma
  • .wmv
  • .wpd
  • .wps
  • .wsf
  • .xcodeproj
  • .xhtml
  • .xlc
  • .xlm
  • .xlr
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .xml
  • .yuv
  • .zip
  • .zipx

It renames encrypted files using the following names:

  • {original file name}.crypt

NOTES:

This ransomware steals the following information from the following programs:

  • FlashFXP 3
  • FlashFXP 4
  • FileZilla
  • FTPRush
  • VanDyke
  • FTP Explorer
  • SmartFTP
  • TurboFTP
  • FTPRush
  • Ipswitch WS_FTP
  • Far FTP
  • Far2 FTP
  • CuteFTP 7 Professional
  • CuteFTP 8 Professional
  • CuteFTP 8 Home
  • CuteFTP 6 Professional
  • CuteFTP 6 Home
  • CuteFTP 7 Home
  • Windows Commander
  • Total Commander
  • Bullet Proof FTP
  • Bullet Proof FTP
  • Sota FFFTP
  • FTPWare COREFTP
  • FTPClient
  • SoftX.org FTPClient
  • Digsby
  • MySpace
  • Pidgin
  • Trillian
  • Google Talk
  • Paltalk
  • Windows Live Mail
  • Scribe
  • Outlook
  • Outlook Express
  • Internet Account Manager

It also steals information from cookies, Google Chrome User Data, and Bitcoin wallet files containing the following in their file name:

  • WALLET
  • _WALLET
  • .WALLET

It checks if it is being run in a virtual environment by checking mouse activity and querying the registry entry:

HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString

It drops the following files whenever it is able to encrypt files:

de_crypt_readme.bmp

de_crypt_readme.html

de_crypt_readme.txt

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.476.05

FIRST VSAPI PATTERN DATE:

19 Apr 2016

VSAPI OPR PATTERN File:

12.477.00

VSAPI OPR PATTERN Date:

20 Apr 2016

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 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

Restore this modified 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\Control Panel\Desktop
    • From: Pattern = ""
      To: Pattern = "{User Preference}"
  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • From: TileWallpaper = "0"
      To: TileWallpaper = "{User Preference}"
  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • From: Wallpaper = "%System Root%\Python{version}\tcl\tk{version}\demos\images\de_crypt_readme.bmp"
      To: Wallpaper = "{User Preference}"

Step 4

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%\Application Data\{random file name}.dat
  • de_crypt_readme.bmp
  • de_crypt_readme.html
  • de_crypt_readme.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as RANSOM_WALTRIX.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 6

Restore encrypted files from backup.


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