Analysis by: Marvelous Pelin
ALIASES:

Ransom.TeslaWare(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, 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 encrypts files with specific file extensions. It encrypts files found in specific folders.

  TECHNICAL DETAILS

File Size: 402,432 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 May 2017
Payload: Encrypts 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 files:

  • %Desktop%\READ_ME.txt - ransom note

(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.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MicrosoftAudioDriver = {malware path}

Process Termination

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

  • Taskmgr
  • processexplorer
  • ProcessHacker

Download Routine

This Ransomware accesses the following websites to download files:

  • http://{BLOCKED}tuff-here.{BLOCKED}e.net/RW\image.jpg
  • http://{BLOCKED}tuff-here.{BLOCKED}e.net/RW\voice.vbs

It saves the files it downloads using the following names:

  • %User Temp%\image.jpg
  • %User Temp%\speaks.vbs

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .3dm
  • .3g2
  • .3gp
  • .aaf
  • .accdb
  • .aep
  • .aepx
  • .aet
  • .ai
  • .aif
  • .arw
  • .as
  • .as3
  • .asf
  • .asp
  • .asx
  • .avi
  • .bay
  • .bmp
  • .cdr
  • .cer
  • .class
  • .cpp
  • .cr2
  • .crt
  • .crw
  • .cs
  • .csv
  • .db
  • .dbf
  • .dcr
  • .der
  • .dng
  • .doc
  • .docb
  • .docm
  • .docx
  • .dot
  • .dotm
  • .dotx
  • .dwg
  • .dxf
  • .dxg
  • .efx
  • .eps
  • .erf
  • .fla
  • .flv
  • .idml
  • .iff
  • .indb
  • .indd
  • .indl
  • .indt
  • .inx
  • .jar
  • .java
  • .jpeg
  • .jpg
  • .kdc
  • .m3u
  • .m3u8
  • .m4u
  • .max
  • .mdb
  • .mdf
  • .mef
  • .mid
  • .mov
  • .mp3
  • .mp4
  • .mpa
  • .mpeg
  • .mpg
  • .mrw
  • .msg
  • .nef
  • .nrw
  • .odb
  • .odc
  • .odm
  • .odp
  • .ods
  • .odt
  • .orf
  • .p12
  • .p7b
  • .p7c
  • .pdb
  • .pdf
  • .pef
  • .pem
  • .pfx
  • .php
  • .plb
  • .pmd
  • .png
  • .pot
  • .potm
  • .potx
  • .ppam
  • .ppj
  • .pps
  • .ppsm
  • .ppsx
  • .ppt
  • .pptm
  • .pptx
  • .prel
  • .ps
  • .psd
  • .pst
  • .ptx
  • .r3d
  • .ra
  • .raf
  • .rar
  • .raw
  • .rb
  • .rtf
  • .rw2
  • .rwl
  • .sdf
  • .sldm
  • .sldx
  • .sql
  • .sr2
  • .srf
  • .srw
  • .svg
  • .swf
  • .tif
  • .txt
  • .vcf
  • .vob
  • .wav
  • .wb2
  • .wma
  • .wmv
  • .wpd
  • .wps
  • .x3f
  • .xla
  • .xlam
  • .xlk
  • .xll
  • .xlm
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .xml
  • .xqx
  • .zip

It encrypts files found in the following folders:

  • Drives from A-Z.

It renames encrypted files using the following names:

  • {random filename}.Yugo

NOTES:
It displays the following after execution:

The ransom note contains the following:

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.470.08
FIRST VSAPI PATTERN DATE: 14 Jun 2017
VSAPI OPR PATTERN File: 13.471.00
VSAPI OPR PATTERN Date: 15 Jun 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

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • MicrosoftAudioDriver = {malware path}

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.
  • %Desktop%\READ_ME.txt
  • %User Temp%\image.jpg
  • %User Temp%\speaks.vbs

Step 6

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