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RANSOM_CRYPTBTN.A

November 03, 2016
 Analysis by: Jeanne Jocson
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

This Trojan may arrive bundled with malware packages as a malware component. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

21,504 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

25 Oct 2016

Payload:

Displays message/message boxes

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Other System Modifications

This Trojan creates the following registry key/entry to trick users into thinking that it is a legitimate application:

HKEY_CURRENT_USER\Software\Microsoft\
Direct3D\MostRecentApplication
Name = "{malware path}"

Dropping Routine

This Trojan drops the following files:

  • C:\Program Files\Windows Defender\hosts.locked

Other Details

This Trojan does the following:

  • Searches for the files with the following extensions in all drives:
    • .doc
    • .xls
    • .ppt
    • .txt
    • .bmp
    • .jpg
    • .gif
    • .jpeg
    • .mpeg
    • .avi
    • .zip
    • .rar
    • .pdf
    • .accdb
    • .db
    • .mdb
    • .bak

NOTES:

This ransomware displays the following as ransom note:

It directs to the following URL when the "Buy BitCoin" button was clicked:

  • https://www.youtube.com/watch?v={BLOCKED}J3Q9g
  • https://www.{BLOCKED}e.com/en

This ransomware doesn't have the capability of encrypting files but has the intention of encrypting files and use it for ransom.

It may be used as a component of other malwares.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.858.05

FIRST VSAPI PATTERN DATE:

25 Oct 2016

VSAPI OPR PATTERN File:

12.859.00

VSAPI OPR PATTERN Date:

26 Oct 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

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:\Program Files\Windows Defender\hosts.locked

Step 4

Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYPTBTN.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 5

Delete this registry key

[ 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.

RESTORE
  • Close Registry Editor.


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