RANSOM_HIDDENTEARDOLPHIN.A

 Analysis by: Marvelous Pelin

 ALIASES:

Ransom.HiddenTear(Malwarebytes)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

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.

  TECHNICAL DETAILS

File Size:

572,416 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

29 May 2017

Payload:

Connects to URLs/IPs, Steals information, Encrypts files, Displays graphics/image, 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 drops the following files:

  • %Desktop%\test\LIES_MICH.txt

(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.)

It creates the following folders:

  • %Desktop%\test

(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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 Ransomware sets the system's desktop wallpaper to the following image:

Download Routine

This Ransomware accesses the following websites to download files:

  • https://2.bp.{BLOCKED}ot.com/{BLOCKED}ew/VPP0osobptI/AAAAAAAABSg/xHadgw6nblA/s1600/code.jpg

It saves the files it downloads using the following names:

  • %User Profile%\picture.jpg - set as desktop wallpaper

(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 and 7.)

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:

  • http://{BLOCKED}.{BLOCKED}.117.80/ransomware/write.php?info={gathered information}

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .3dm
  • .3DS
  • .3g2
  • .3GP
  • .7Z
  • .ACCDB
  • .ai
  • .AIF
  • .APK
  • .app
  • .ASF
  • .asp
  • .ASPX
  • .AVI
  • .bat
  • .BMP
  • .cer
  • .cfm
  • .CGI
  • .COM
  • .crx
  • .csr
  • .CSS
  • .CSV
  • .dat
  • .DB
  • .dbf
  • .dds
  • .dem
  • .doc
  • .DOCX
  • .DWG
  • .DXF
  • .EPS
  • .exe
  • .flv
  • .gadget
  • .gam
  • .GED
  • .GIF
  • .gpx
  • .HTM
  • .html
  • .ics
  • .IFF
  • .INDD
  • .JAR
  • .jpeg
  • .JPG
  • .JS
  • .jsp
  • .KEY
  • .KEYCHAIN
  • .kml
  • .kmz
  • .log
  • .M3U
  • .M4A
  • .M4V
  • .max
  • .MDB
  • .MID
  • .MOV
  • .MP3
  • .mp4
  • .mpa
  • .MPG
  • .MSG
  • .msi
  • .NES
  • .obj
  • .odt
  • .OTF
  • .pages
  • .part
  • .PCT
  • .PDB
  • .pdf
  • .php
  • .PLUGIN
  • .PNG
  • .pps
  • .PPT
  • .PPTX
  • .ps
  • .PSD
  • .pspimage
  • .RAR
  • .RM
  • .ROM
  • .RSS
  • .RTF
  • .SAV
  • .SDF
  • .sql
  • .SRT
  • .SVG
  • .swf
  • .TAR
  • .tar.gz
  • .TAX2016
  • .TEX
  • .tga
  • .THM
  • .TIF
  • .TIFF
  • .torrent
  • .TXT
  • .vcf
  • .VOB
  • .wav
  • .WMA
  • .wmv
  • .wpd
  • .wps
  • .wsf
  • .xhtml
  • .XLR
  • .xls
  • .XLSX
  • .XML
  • .yuv
  • .zip
  • .zipx

It renames encrypted files using the following names:

  • {original filename and extension}.dolphin

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

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.436.04

FIRST VSAPI PATTERN DATE:

29 May 2017

VSAPI OPR PATTERN File:

13.437.00

VSAPI OPR PATTERN Date:

30 May 2017

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

Restart in Safe Mode

[ Learn More ]

Step 4

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.  
  • %Desktop%\test

Step 5

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.
  • %User Profile%\picture.jpg

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_HIDDENTEARDOLPHIN.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 7

Restore encrypted files from backup.


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