Analysis by: Joshua Maigue
 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • 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 encrypts files with specific file extensions. It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 209,408 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 16 Dec 2020
Payload: Displays graphics/image, Drops files, 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.

Installation

This Ransomware drops the following copies of itself into the affected system:

  • %System%\{MALWARE NAME}.exe

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

It adds the following processes:

  • "%System%\WindowsPowerShell\v1.0\powershell.exe" Add-MpPreference -ExclusionPath "{MALWARE PATH}\{MALWARE NAME}.exe" -Force;
  • {MALWARE LOCATION}\{MALWARE NAME}.EXE

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{MALWARE NAME}.exe = %System%\{MALWARE NAME}.exe

It drops the following file(s) in the Startup Items folder to enable its automatic execution at every system startup:

  • %User Startup%\{MALWARE NAME}.exe
  • %Common Startup%\{MALWARE NAME}.exe

(Note: %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 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).. %Common Startup% is the startup folder for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Other Details

This Ransomware does the following:

  • Modifies the following Windows Defender Actions for defense evasion:
    • DisableAntiSpyware
    • DisableBehaviorMonitoring
    • DisableOnAccessProtection
    • DisableScanOnRealtimeEnable
  • It deletes shadow copies by executing the following command:
    • vssadmin delete shadows /all /quiet
  • It sets the currently active code page to 1251 by executing the following command:
    • mode con cp select=1251
  • It encrypts files in all fixed, remote and removable drives.
  • After encrypting files it execute "info.hta" and "info.hta" displays the following:

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .1cd
  • .3g2
  • .3gp
  • .3fr
  • .accda
  • .3ds
  • .accdb
  • .accdc
  • .accde
  • .accdt
  • .accdw
  • .adb
  • .adp
  • .ai3
  • .ai4
  • .ai5
  • .ai6
  • .ai7
  • .ai8
  • .anim
  • .arw
  • .asa
  • .asc
  • .ascx
  • .asm
  • .asmx
  • .asp
  • .aspx
  • .asr
  • .asx
  • .avi
  • .avs
  • .backup
  • .bak
  • .bay
  • .bin
  • .bmp
  • .bz2
  • .cdr
  • .cer
  • .cfc
  • .cfm
  • .cfml
  • .cfu
  • .chm
  • .cin
  • .class
  • .clx
  • .config
  • .cpp
  • .cr2
  • .crt
  • .crw
  • .css
  • .csv
  • .cub
  • .dae
  • .dat
  • .dbf
  • .dbx
  • .dc3
  • .dcm
  • .dcr
  • .der
  • .dib
  • .dic
  • .dif
  • .divx
  • .djvu
  • .dng
  • .doc
  • .docm
  • .docx
  • .dot
  • .dotm
  • .dotx
  • .dpx
  • .dqy
  • .dsn
  • .dtd
  • .dwg
  • .dwt
  • .dxf
  • .edml
  • .efd
  • .elf
  • .emf
  • .emz
  • .epf
  • .eps
  • .epsf
  • .epsp
  • .erf
  • .exr
  • .f4v
  • .fido
  • .flm
  • .flv
  • .frm
  • .fxg
  • .geo
  • .gif
  • .grs
  • .hdr
  • .hpp
  • .hta
  • .htc
  • .htm
  • .html
  • .icb
  • .ics
  • .iff
  • .inc
  • .indd
  • .ini
  • .iqy
  • .j2c
  • .j2k
  • .java
  • .jp2
  • .jpc
  • .jpe
  • .jpeg
  • .jpf
  • .jpg
  • .jpx
  • .jsf
  • .json
  • .jsp
  • .kdc
  • .kmz
  • .kwm
  • .lasso
  • .lbi
  • .lgf
  • .lgp
  • .log
  • .m1v
  • .m4a
  • .m4v
  • .max
  • .mda
  • .mdb
  • .mde
  • .mdf
  • .mdw
  • .mef
  • .mft
  • .mfw
  • .mht
  • .mhtml
  • .mka
  • .mkidx
  • .mkv
  • .mos
  • .mov
  • .mp3
  • .mp4
  • .mpeg
  • .mpg
  • .mpv
  • .mrw
  • .msg
  • .mxl
  • .myd
  • .myi
  • .nef
  • .nrw
  • .obj
  • .odb
  • .odc
  • .odm
  • .odp
  • .ods
  • .oft
  • .one
  • .onepkg
  • .opt
  • .oqy
  • .orf
  • .p12
  • .p7b
  • .p7c
  • .pam
  • .pbm
  • .pct
  • .pcx
  • .pdd
  • .pdf
  • .pdp
  • .pef
  • .pem
  • .pff
  • .pfm
  • .pfx
  • .pgm
  • .php
  • .php3
  • .php4
  • .php5
  • .phtml
  • .pict
  • .pls
  • .png
  • .pnm
  • .pot
  • .potm
  • .potx
  • .ppa
  • .ppam
  • .ppm
  • .pps
  • .ppsm
  • .ppt
  • .pptm
  • .pptx
  • .prn
  • .psb
  • .psd
  • .pst
  • .ptx
  • .pub
  • .pwm
  • .pxr
  • .r3d
  • .raf
  • .rar
  • .raw
  • .rdf
  • .rgbe
  • .rle
  • .rqy
  • .rss
  • .rtf
  • .rw2
  • .rwl
  • .safe
  • .sct
  • .sdpx
  • .shtm
  • .shtml
  • .slk
  • .sln
  • .sql
  • .sr2
  • .srf
  • .srw
  • .ssi
  • .stm
  • .svg
  • .svgz
  • .swf
  • .tab
  • .tar
  • .tbb
  • .tbi
  • .tbk
  • .tdi
  • .tga
  • .thmx
  • .tif
  • .tiff
  • .tld
  • .tpl
  • .txt
  • .u3d
  • .udl
  • .uxdc
  • .vbs
  • .vcs
  • .vda
  • .vdr
  • .vdw
  • .vdx
  • .vrp
  • .vsd
  • .vss
  • .vst
  • .vsw
  • .vsx
  • .vtm
  • .vtml
  • .vtx
  • .wb2
  • .wav
  • .wbm
  • .wbmp
  • .wim
  • .wmf
  • .wml
  • .wmv
  • .wpd
  • .wps
  • .x3f
  • .xla
  • .xlam
  • .xlk
  • .xlm
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .xml
  • .xps
  • .xsd
  • .xsf
  • .xsl
  • .xslt
  • .xsn
  • .xtp
  • .xtp2
  • .xyze
  • .zip

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

  • .[{BLOCKED}les@{BLOCKED}u.club].lock

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

  • %Desktop%\FILES ENCRYPTED.txt
  • {Encrypted Drives}\FILES ENCRYPTED.txt
  • %Common Programs%\info.hta
  • %Programs%\info.hta

(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).. %Common Programs% is the folder that contains common program groups for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs on Windows Vista, 7, and 8.. %Programs% is the folder that contains the user’s program groups, which is usually C:\Windows\Start Menu\Programs or C:\Documents and Settings\{User name}\Start Menu\Programs on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs on Windows Vista, 7, and 8.)

It leaves text files that serve as ransom notes containing the following text:

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.422.02
FIRST VSAPI PATTERN DATE: 18 Dec 2020
VSAPI OPR PATTERN File: 16.423.00
VSAPI OPR PATTERN Date: 19 Dec 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.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

Identify and terminate files detected as Ransom.Win32.CRYSIS.TIBGHB

[ 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

Delete this registry value

[ 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {MALWARE NAME}.exe = %System%\{MALWARE NAME}.exe

Step 6

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.
  • %Desktop%\FILES ENCRYPTED.txt
  • {Encrypted Drives}\FILES ENCRYPTED.txt
  • %Common Programs%\info.hta
  • %Programs%\info.hta

Step 7

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.CRYSIS.TIBGHB. 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 8

Restore encrypted files from backup.


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