Analysis by: Arianne Grace Dela Cruz
ALIASES:

Ransom:Win32/Lazpark.DA!MTB (MICROSOFT); VHO:Trojan-Ransom.Win32.Agent.gen (KASPERSKY)

 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

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. It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size: 303,616 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 17 Apr 2021
Payload: Displays message/message boxes, Encrypts files

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.

Process Termination

This Ransomware terminates the following processes if found running in the affected system's memory:

  • All processes excluding those with the following names:
    • powershell.exe
    • rundll32.exe
    • werfault.exe
    • explorer.exe
    • vmnetdhcp.exe
    • vmware-authd.exe
    • vmware-hostd.exe
    • vmware-tray.exe
    • vmware-usbarbitrator64.exe
    • vmware-usbarbitrator32.exe
    • webroot_updater.exe
    • windowsupdate.exe
    • vmware-usbarbitrator.exe

Other Details

This Ransomware does the following:

  • It displays the following upon execution:
  • Encrypts the following drive types:
    • Fixed drive
    • Removable drive
    • Remote drive

It accepts the following parameters:

  • --kill-susp -> to trigger process termination

Ransomware Routine

This Ransomware avoids encrypting files with the following strings in their file name:

  • autorun.inf
  • boot.ini
  • bootfont.bin
  • bootsect.bak
  • desktop.ini
  • iconcache.db
  • ntldr
  • ntuser.dat
  • ntuser.dat.log
  • ntuser.ini
  • thumbs.db
  • bootmgr
  • !{company name}!howtodecipher.txt
  • ! cynet ransom protection(don't delete)

It avoids encrypting files found in the following folders:

  • %Windows%
  • :\$RECYCLE.BIN\
  • \windows\system32\
  • \windows\syswow64\
  • \windows\system\
  • \windows\winsxs\
  • \System\msadc\
  • \Common Files\
  • \WindowsPowerShell\
  • \Program Files\Internet Explorer\
  • \Program Files\Microsoft Games\
  • \all users\microsoft\
  • \inetpub\logs\
  • :\boot\
  • :\system volume information\
  • :\drivers\
  • :\wsus\
  • \cache\
  • \cache2\
  • \far manager\
  • \ida 7.0\
  • \ida 6.8\
  • \Temporary Internet Files\
  • \Temp\
  • $windows.~bt
  • $windows.~ws
  • \google\
  • \mozilla\
  • \tor browser\
  • \windows.old\
  • \intel\
  • \msocache\
  • \perflogs\
  • \ProgramData\Microsoft\
  • \Application Data\Microsoft\
  • \All Users\Microsoft\
  • \Roaming\Microsoft\
  • \Local\Microsoft\
  • \Local Settings\Microsoft\
  • \LocalLow\Microsoft\
  • \Common\Microsoft\
  • \Sophos\
  • \Symantec\
  • \Leaked\

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

It appends the following extension to the file name of the encrypted files:

  • .{company name}-jamn2bat

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

  • {Encrypted directory}\!{company name}!howtodecipher.txt

It avoids encrypting files with the following file extensions:

  • ani
  • ax
  • bat
  • cab
  • cmd
  • cpl
  • cur
  • deskthemepack
  • diagcab
  • diagpkg
  • dll
  • drv
  • exe
  • hlp
  • hta
  • icl
  • icns
  • ico
  • ics
  • idx
  • inf
  • iso
  • lnk
  • mod
  • mpa
  • msc
  • msi
  • msp
  • msstyles
  • mst
  • msu
  • mui
  • nls
  • nomedia
  • ntldr
  • ocx
  • pf
  • prf
  • rom
  • rtp
  • scr
  • shs
  • spl
  • sys
  • theme
  • themepack
  • url
  • {company name}-jamn2bat

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.860.02
FIRST VSAPI PATTERN DATE: 23 Jul 2021
VSAPI OPR PATTERN File: 16.861.00
VSAPI OPR PATTERN Date: 24 Jul 2021

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.XXPE50FFF043

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

Restart in Safe Mode

[ Learn More ]

Step 5

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.
  • {Encrypted directory}\!{company name}!howtodecipher.txt

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.SFILE.AB. 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 7

Restore encrypted files from backup.


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