Ransom.Win32.CRYPTOPXJ.A

March 27, 2020
 Analysis by: Mc Justine De Guzman
 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 drops files as ransom note.

  TECHNICAL DETAILS

File Size:

114,688 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 Feb 2020

Payload:

Encrypts files, Empties recycle bin, Drops other malware/grayware

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 adds the following processes:

  • vssadmin.exe delete shadows /all /quiet
  • bcdedit.exe /set {default} recoveryenabled no
  • bcdedit.exe /set {current} bootstatuspolicy ignoreallfailures
  • bcdedit.exe /set {default} recoveryenabled no
  • bcdedit.exe /set {current} bootstatuspolicy ignoreallfailures

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • XVFXGW DOUBLE SET

Dropping Routine

This Ransomware drops the following files:

  • {malware path}\Res.AAABANIx93RdufO4

Other Details

This Ransomware does the following:

  • It encrypts every file with extension regardless if it's a legitimate extension or not
  • It empties the recycle bin on all drives

Ransomware Routine

This Ransomware appends the following extension to the file name of the encrypted files:

  • .pxj

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

  • %Desktop%\LOOK.TXT
  • %System Root%\LOOK.TXT

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.714.02

FIRST VSAPI PATTERN DATE:

29 Feb 2020

VSAPI OPR PATTERN File:

15.715.00

VSAPI OPR PATTERN Date:

01 Mar 2020

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • Troj.Win32.TRX.XXPE50FFF034

Step 2

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 3

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 4

Identify and terminate files detected as Ransom.Win32.CRYPTOPXJ.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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%\LOOK.TXT
  • %System Root%\LOOK.TXT

Step 6

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.CRYPTOPXJ.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 the following Trend Micro Support pages for more information:

Step 7

Restore encrypted files from backup.

Step 8

Enabling Startup Repair

  1. Run the command prompt (cmd.exe) as administrator.
  2. Enable Startup Repair by typing the following command:
    /bcedit /set {default} recoveryenabled Yes


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