RANSOM_STOPI.F116IT


 ALIASES:

Trojan:Win32/Skeeyah.A!bit (Microsoft), Ransom.Apocalypse (Malwarebytes)

 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:

Downloaded from the Internet, Dropped by other malware

This Trojan 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:

337,096 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

16 Mar 2016

Payload:

Drops files, Encrypts files, Renames files

Arrival Details

This Trojan 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 Trojan drops the following copies of itself into the affected system and executes them:

  • %User Temp%\qinYrfQ1xrP438n.exe

(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.)

It drops the following files:

  • {directory of encrypted files}\HOW TO DECRYPT FILES.txt - ransom note

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

  • Interpol !!! You broke the law !! All your files are blocked !! To restore your files visit http://{BLOCKED}dpiracy.host.sk ;If the site is not working please write to email {BLOCKED}cy@email.su Your id {BLOCKED}

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Alcmeter = %User Temp%\qinYrfQ1xrP438n.exe

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\.7m2oLM

HKEY_CLASSES_ROOT\CZATEDRMCHUGWNL\DefaultIcon

HKEY_CLASSES_ROOT\CZATEDRMCHUGWNL\shell\
open\command

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.7m2oLM

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CZATEDRMCHUGWNL\DefaultIcon

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CZATEDRMCHUGWNL\shell\open\
command

It adds the following registry entries:

HKEY_CLASSES_ROOT\.7m2oLM

HKEY_CLASSES_ROOT\CZATEDRMCHUGWNL

HKEY_CLASSES_ROOT\CZATEDRMCHUGWNL\DefaultIcon

HKEY_CLASSES_ROOT\CZATEDRMCHUGWNL\shell\
open\command

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.7m2oLM

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CZATEDRMCHUGWNL

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CZATEDRMCHUGWNL\DefaultIcon

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CZATEDRMCHUGWNL\shell\open\
command

Other Details

This Trojan encrypts files with the following extensions:

  • .zip
  • .rar
  • .tar
  • .gzip
  • .jpg
  • .jpeg
  • .psd
  • .cdr
  • .dwg
  • .max
  • .bmp
  • .gif
  • .png
  • .doc
  • .docx
  • .xls
  • .xlsx
  • .ppt
  • .pptx
  • .txt
  • .pdf
  • .djvu
  • .htm
  • .html
  • .mdb
  • .cer
  • .p12
  • .pfx
  • .kwm
  • .pwm
  • .1cd
  • .mdf
  • .dbf
  • .odt
  • .vob
  • .ifo
  • .torrent
  • .mov
  • .m2v
  • .3gp
  • .mpeg
  • .mpg
  • .flv
  • .avi
  • .mp4
  • .wmv
  • .divx
  • .mkv
  • .mp3
  • .wav
  • .flac
  • .ape
  • .wma
  • .ac3
  • .dwg

It renames encrypted files using the following names:

  • {file name}.{file extension}.7m2oLM

NOTES:

The ransomware changes the icon of all encrypted files to the following:

The ransomware displays the following message box after encrypting files:

Once the "okay" button is clicked, it changes the wallpaper to the following:

It also closes the Windows Explorer.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.806.08

FIRST VSAPI PATTERN DATE:

23 Sep 2016

VSAPI OPR PATTERN File:

12.807.00

VSAPI OPR PATTERN Date:

24 Sep 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

Restart in Safe Mode

[ Learn More ]

Step 4

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.

  • In HKEY_CLASSES_ROOT
    • .7m2oLM
  • In HKEY_CLASSES_ROOT
    • CZATEDRMCHUGWNL
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • .7m2oLM
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • CZATEDRMCHUGWNL

Step 5

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Alcmeter = "%User Temp%\qinYrfQ1xrP438n.exe"

Step 6

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.
  • {directory of encrypted files}\HOW TO DECRYPT FILES.txt

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_STOPI.F116IT. 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 8

Restore encrypted files from backup.


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