Analysis by: James Vargas
ALIASES:

Trojan-Dropper.Win32.Delf {IKARUS}; Backdoor.Bladabindi {VBA32}

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • 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: 1,231,360 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 15 Dec 2020
Payload: Drops files, Disables services, , Encrypts files, Displays message/message boxes

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 files:

  • %public%\Desktop\list.hello → List of all encrypted files
  • %Desktop%\list.hello → List of all encrypted files
  • %All Users Profile%\Microsoft\Crypto\RSA\MachineKeys\{random GUID}

(Note: %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

It adds the following processes:

  • "%System%\vssadmin.exe" delete shadows /all → Deletes shadow copy
  • "powershell.exe" Dismount-DiskImage "{Found filepath.vhd}" → Dismounts Virtual Drives

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Process Termination

This Ransomware terminates the following services if found on the affected system:

  • mssql
  • sql
  • postgresql
  • oracle
  • mysql
  • veeam
  • backup

Other Details

This Ransomware encrypts files with the following extensions:

  • *.txt
  • *.doc?
  • *.xls?
  • *.ppt?
  • *.pdf
  • *.csv
  • *.zip?
  • *.rar?
  • *.7z?
  • *.gz?
  • *.sql
  • *.mdf
  • *.myd
  • *.ibd
  • *_fsm
  • *_vm
  • *.db?
  • *.rpt

It does the following:

  • It deletes files with following extensions in their filenames:
    • *.bak
    • *.bk
    • *.vbk
    • *.vbm
    • *.vhd
  • It deletes files with following strings in their filenames:
    • *backup*
  • It requires a specific argument to proceed with its encryption routine.

Ransomware Routine

This Ransomware avoids encrypting files found in the following folders:

  • %Windows%\
  • %All Users Profile%\
  • %System Root%\$recycle bin\
  • %System Root%\Common Files\
  • %System Root%\windowspowershell\

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). . %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

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

  • .hello

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

  • %public%\Desktop\Readme!!!.txt
  • %Desktop%\Readme!!!.txt

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.582.05
FIRST VSAPI PATTERN DATE: 08 Mar 2021
VSAPI OPR PATTERN File: 16.583.00
VSAPI OPR PATTERN Date: 09 Mar 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.XXPE50FFF039

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

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.
  • %public%\Desktop\list.hello
  • %Desktop%\list.hello
  • %public%\Desktop\Readme!!!.txt
  • %Desktop%\Readme!!!.txt
  • %All Users Profile%\Microsoft\Crypto\RSA\MachineKeys\{random GUID}

Step 5

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.HELLO.YALP-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 6

Restore encrypted files from backup.


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