Ransom.Win32.CRYSIS.NDJ

December 06, 2018
 Analysis by: Kiyoshi Obuchi
 ALIASES:

Ransom:Win32/Wadhrama.C (Microsoft); Ransom-WW!9590EF00D039 (McAfee); Troj/Criakl-G (Sophos)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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 is capable of encrypting files in the affected system.

It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

94,720 bytes

File Type:

EXE

Initial Samples Received Date:

18 Nov 2018

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 copies of itself into the affected system:

  • %System%\{malware filename}.exe
  • %User Startup%\{malware filename}.exe
  • %All Users Profile%\{malware filename}.exe
  • %Application Data%\{malware filename}.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000, XP, and Server 2003, or C:\ProgramData on Windows Vista, 7, and 8. . %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Malware Filename}.exe = %Application Data%\{Malware Filename}.exe

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
{Malware Filename}.exe = %System%\{Malware Filename}.exe

Other Details

This Ransomware is capable of encrypting files in the affected system.

Ransomware Routine

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

  • .id-{ID}.[{BLOCKED}abad1976@aol.com].adobe

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

  • %System%\Info.hta
  • {Removable Drive}\FILES ENCRYPTED.txt
  • %Desktop%\FILES ENCRYPTED.txt
  • %User Startup%\Info.hta
  • %Application Data%\Info.hta

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista, 7, and 8.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.670.03

FIRST VSAPI PATTERN DATE:

06 Dec 2018

VSAPI OPR PATTERN File:

14.671.00

VSAPI OPR PATTERN Date:

07 Dec 2018

Step 1

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 2

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {Malware Filename}.exe = %Application Data%\{Malware Filename}.exe
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • {Malware Filename}.exe = %System%\{Malware Filename}.exe

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.  
  • %System%\Info.hta
  • {Removable Drive}\FILES ENCRYPTED.txt
  • %Desktop%\FILES ENCRYPTED.txt
  • %User Startup%\Info.hta
  • %Application Data%\Info.hta

Step 6

Restore encrypted files from backup.

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.CRYSIS.NDJ. 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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