RANSOM.WIN32.FLYTERPER.THIOGAH

 Analysis by: Michael Jhon Ofiaza

 ALIASES:

Ransom:MSIL/Ryzerlo.A (Microsoft) ; Gen:Heur.Ransom.REntS.Gen.1 (Bitdefender)

 PLATFORM:

Windows

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

  • 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 connects to certain websites to send and receive information.

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

  TECHNICAL DETAILS

File Size:

228,864 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

29 Aug 2018

Payload:

Collects system information, Connects to URLs/IPs, Creates files, Displays message/message boxes, Steals information, 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:

  • C:\{Username}\run11\local.exe.CRYPTR

It creates the following folders:

  • C:\{Username}\run11

Other System Modifications

This Ransomware changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = C:\{Username}\CRYPTR.jpg

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

Download Routine

This Ransomware accesses the following websites to download files:

  • https://{BLOCKED}.{BLOCKED}r.com/0i1ZFth.jpg

It saves the files it downloads using the following names:

  • C:\{Username}\CRYPTR.jpg

Information Theft

This Ransomware gathers the following data:

  • Computer Name
  • Username

Other Details

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

  • https://{BLOCKED}0r.{BLOCKED}pp.com/access/access.php?info=

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .txt
  • .jar
  • .exe
  • .dat
  • .contact
  • .settings
  • .doc
  • .docx
  • .xls
  • .xlsx
  • .ppt
  • .pptx
  • .odt
  • .jpg
  • .png
  • .csv
  • .py
  • .sql
  • .sqlite
  • .sqlite3
  • .mdb
  • .sln
  • .php
  • .asp
  • .aspx
  • .html
  • .htm
  • .xml
  • .psd
  • .pdf
  • .dll
  • .c
  • .cs
  • .mp3
  • .mp4
  • .f3d
  • .dwg
  • .cpp
  • .zip
  • .rar
  • .mov
  • .rtf
  • .bmp
  • .mkv
  • .avi
  • .apk
  • .lnk
  • .iso
  • .7-zip
  • .ace
  • .arj
  • .bz2
  • .cab
  • .gzip
  • .lzh
  • .tar
  • .uue
  • .xz
  • .z
  • .001
  • .mpeg
  • .mpg
  • .core
  • .crproj
  • .pdb
  • .ico
  • .pas
  • .db
  • .torrent
  • .file
  • .jquery
  • .css
  • .md
  • .pl
  • .pyw
  • .key
  • .bin
  • .phtml
  • .php2
  • .php3
  • .php4
  • .php5
  • .gpg
  • .webm
  • .rc
  • .rb
  • .js
  • .java
  • .lst
  • .settingcontent-ms
  • .bash
  • .bashrc
  • .bash_profil
  • .bat
  • .jso
  • .py.old
  • .vb
  • .vbs
  • .sample
  • .locked
  • .locky
  • .opax
  • .opal
  • .chm
  • .crt

It encrypts files found in the following folders:

  • C:\Users\{Username}\Desktop
  • C:\Users\{Username}\Links
  • C:\Users\{Username}\Contacts
  • C:\Users\{Username}\Desktop
  • C:\Users\{Username}\Documents
  • C:\Users\{Username}\Downloads
  • C:\Users\{Username}\Pictures
  • C:\Users\{Username}\Music
  • C:\Users\{Username}\OneDrive
  • C:\Users\{Username}\Saved Games
  • C:\Users\{Username}\Favorites
  • C:\Users\{Username}\Searches
  • C:\Users\{Username}\Videos
  • D:\{All folders in Drive D:}

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

  • .CRYPTR

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

  • C:\Users\{Username}\Desktop\ATTANTION!!!.txt
  • C:\Users\{Username}\Desktop\INTRUCTION.html
  • C:\Users\{Username}\Desktop\PAYMENT !!!.txt

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.554.01

FIRST VSAPI PATTERN DATE:

09 Oct 2018

VSAPI OPR PATTERN File:

14.555.00

VSAPI OPR PATTERN Date:

10 Oct 2018

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

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • C:\{Username}\run11

Step 4

Search and delete this file

[ 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.
  • C:\Users\{Username}\Desktop\ATTANTION!!!.txt
  • C:\Users\{Username}\Desktop\INTRUCTION.html
  • C:\Users\{Username}\Desktop\PAYMENT !!!.txt
  • C:\{Username}\CRYPTR.jpg

Step 5

Scan your computer with your Trend Micro product to delete files detected as RANSOM.WIN32.FLYTERPER.THIOGAH. 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 6

Reset your Desktop properties

[ Learn More ]

Step 7

Restore encrypted files from backup.


Did this description help? Tell us how we did.