Modified by: Kiyoshi Obuchi
 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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 drops files as ransom note.

  TECHNICAL DETAILS

File Size: 54,784 bytes
File Type: EXE
Initial Samples Received Date: 14 Jun 2019

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:

  • %application data%\{malware file name}.exe

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\RunOnce
BrowserUpdateCheck = "%application data%\{malware file name}.exe"

Dropping Routine

This Ransomware drops the following files:

  • %System Root%\Users\Public\4DC7EB8ACBAB74F2FCC865155394EFB34F2AA9539846ADF959FEB8A32C6FD6B6
  • %System Root%\yehey.py
  • %System Root%\config.sys
  • {All Drivesafter %System Root%}\yehey.py
  • %System Root%\autoexec.bat
  • {All Drivesafter %System Root%}\CRAWL.PY
  • %System Root%\CRAWL.PY
  • {All Drivesafter %System Root%}\yehey.py

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Ransomware Routine

This Ransomware renames encrypted files using the following names:

  • {encrypted file}.com}BTC

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

  • {Encrypted Directory}\how_to_back_files.html

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.176.02
FIRST VSAPI PATTERN DATE: 15 Jun 2019
VSAPI OPR PATTERN File: 15.176.03
VSAPI OPR PATTERN Date: 16 Jun 2019

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

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\RunOnce
    • BrowserUpdateCheck = "%application data%\{malware file name}.exe"

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.
  • %System Root%\Users\Public\4DC7EB8ACBAB74F2FCC865155394EFB34F2AA9539846ADF959FEB8A32C6FD6B6
  • %System Root%\yehey.py
  • %System Root%\config.sys
  • {All Drivesafter %System Root%}\yehey.py
  • %System Root%\autoexec.bat
  • {All Drivesafter %System Root%}\CRAWL.PY
  • %System Root%\CRAWL.PY
  • {All Drivesafter %System Root%}\yehey.py
  • {Encrypted Directory}\how_to_back_files.html

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.FAKEGLOBE.AGV. 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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