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RANSOM_ZIPTB.A

August 24, 2016
 Analysis by: John Kevin Sanchez
 ALIASES:

Trojan-Ransom.CTB-Faker (Ikarus), Trojan-Ransom.Win32.Blocker.jinn (Kaspersky), W32/Blocker.JINN!tr (Fortinet)

 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 Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

12 Jul 2016

Payload:

Encrypts files, Displays message/message boxes

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 files:

  • %ProgramData%\help.exe
  • %ProgramData%\index.html - ransom note
  • %ProgramData%\restore.exe - use for restoring the files from the ZIP archive file
  • %ProgramData%\untitled.png
  • %ProgramData%\your personal files are encrypted.txt - ransom note
  • %System Root%\your personal files are encrypted.txt - ransom note

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It drops and executes the following files:

  • %ProgramData%\archiver.vbs
  • %ProgramData%\archiver.bat - creates the password protected ZIP archive of files
  • %ProgramData%\copy.vbs
  • %ProgramData%\copy.bat
  • %ProgramData%\startup.vbs
  • %ProgramData%\startup.exe
  • %ProgramData%\untitled.vbs - opens a fake message box about a graphic card error

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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 drops the following non-malicious files:

  • %ProgramData%\{bundled WinRAR package / components}

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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 Trojan adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
help.exe = %ProgramData%\help.exe

Other Details

This Trojan encrypts files with the following extensions:

  • .exe
  • .msi
  • .dll
  • .jpg
  • .jpeg
  • .bmp
  • .gif
  • .png
  • .psd
  • .mp3
  • .wav
  • .mp4
  • .avi
  • .zip
  • .rar
  • .iso
  • .7z
  • .cab
  • .dat
  • .data

It does the following:

  • The target files are located in %System Root%\Users.
  • It moves the target files into a password protected archive, %System Root%\Users.zip.
  • After encrypting files, it shuts down the system.

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

NOTES:

This Trojan displays the following:

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.652.06

FIRST VSAPI PATTERN DATE:

14 Jul 2016

VSAPI OPR PATTERN File:

12.653.00

VSAPI OPR PATTERN Date:

15 Jul 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

Delete these registry values

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • help.exe = %ProgramData%\help.exe

Step 4

Search and delete these files

[ 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.
  • %ProgramData%\help.exe
  • %ProgramData%\index.html
  • %ProgramData%\restore.exe
  • %ProgramData%\untitled.png
  • %ProgramData%\your personal files are encrypted.txt
  • %System Root%\your personal files are encrypted.txt
  • %ProgramData%\archiver.vbs
  • %ProgramData%\archiver.bat
  • %ProgramData%\copy.vbs
  • %ProgramData%\copy.bat
  • %ProgramData%\startup.vbs
  • %ProgramData%\startup.exe
  • %ProgramData%\untitled.vbs
  • %ProgramData%\{bundled WinRAR package / components}

Step 5

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


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