Ransom.Win32.CRYSIS.APHX

July 11, 2019
 Analysis by: Earle Maui Earnshaw
 ALIASES:

Ransom:Win32/Wadhrama.C(Microsoft); Trojan-Ransom.Win32.Crusis.to(Kaspersky)

 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:

Dropped by other malware, 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 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

Memory Resident:

No

Initial Samples Received Date:

26 Jun 2019

Payload:

Terminates processes, 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.

Installation

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

  • %System%\{Malware Filename}.exe ← (if admin)
  • %Application Data%\{Malware Filename}.exe ← (if non-admin)

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • /c mode con cp select=1251
  • /c vssadmin delete shadows /all /quiet

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

  • Global\syncronize_T2U142A
  • Global\syncronize_T2U142U

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 Filename} = "%System%\{Malware Filename}"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
{Malware Filename} = "%Application Data%\{Malware Filename}"

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

It enables its automatic execution at every system startup by dropping the following copies of itself into the Windows Common Startup folder:

  • %User Startup%\{Malware Filename}.exe
  • %Common Startup%\{Malware Filename}.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 System Modifications

This Ransomware adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
CurrentVersion\Run
%System%\Info.hta = "mshta.exe "%System%\Info.hta""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
%Application Data%\Info.hta = "mshta.exe "%Application Data%\Info.hta""

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
%Application Data%\Info.hta = "mshta.exe "%Application Data%\Info.hta""

Process Termination

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

  • FirebirdGuardianDefaultInstance
  • FirebirdServerDefaultInstance
  • sqlwriter
  • mssqlserver
  • sqlserveradhelper

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

  • 1c8.exe
  • 1cv77.exe
  • outlook.exe
  • postgres.exe
  • mysqld-nt.exe
  • mysqld.exe
  • sqlservr.exe

Other Details

This Ransomware encrypts files with the following extensions:

  • .1cd
  • .3ds
  • .3fr
  • .3g2
  • .3gp
  • .7z
  • .accda
  • .accdb
  • .accdc
  • .accde
  • .accdt
  • .accdw
  • .adb
  • .adp
  • .ai
  • .ai3
  • .ai4
  • .ai5
  • .ai6
  • .ai7
  • .ai8
  • .anim
  • .arw
  • .as
  • .asa
  • .asc
  • .ascx
  • .asm
  • .asmx
  • .asp
  • .aspx
  • .asr
  • .asx
  • .avi
  • .avs
  • .backup
  • .bak
  • .bay
  • .bd
  • .bin
  • .bmp
  • .bz2
  • .c
  • .cdr
  • .cer
  • .cf
  • .cfc
  • .cfm
  • .cfml
  • .cfu
  • .chm
  • .cin
  • .class
  • .clx
  • .config
  • .cpp
  • .cr2
  • .crt
  • .crw
  • .cs
  • .css
  • .csv
  • .cub
  • .dae
  • .dat
  • .db
  • .dbf
  • .dbx
  • .dc3
  • .dcm
  • .dcr
  • .der
  • .dib
  • .dic
  • .dif
  • .divx
  • .djvu
  • .dng
  • .doc
  • .docm
  • .docx
  • .dot
  • .dotm
  • .dotx
  • .dpx
  • .dqy
  • .dsn
  • .dt
  • .dtd
  • .dwg
  • .dwt
  • .dx
  • .dxf
  • .edml
  • .efd
  • .elf
  • .emf
  • .emz
  • .epf
  • .eps
  • .epsf
  • .epsp
  • .erf
  • .exr
  • .f4v
  • .fido
  • .flm
  • .flv
  • .frm
  • .fxg
  • .geo
  • .gif
  • .grs
  • .gz
  • .h
  • .hdr
  • .hpp
  • .hta
  • .htc
  • .htm
  • .html
  • .icb
  • .ics
  • .iff
  • .inc
  • .indd
  • .ini
  • .iqy
  • .j2c
  • .j2k
  • .java
  • .jp2
  • .jpc
  • .jpe
  • .jpeg
  • .jpf
  • .jpg
  • .jpx
  • .js
  • .jsf
  • .json
  • .jsp
  • .kdc
  • .kmz
  • .kwm
  • .lasso
  • .lbi
  • .lgf
  • .lgp
  • .log
  • .m1v
  • .m4a
  • .m4v
  • .max
  • .md
  • .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
  • .onetoc2
  • .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
  • .pl
  • .pls
  • .pm
  • .png
  • .pnm
  • .pot
  • .potm
  • .potx
  • .ppa
  • .ppam
  • .ppm
  • .pps
  • .ppsm
  • .ppt
  • .pptm
  • .pptx
  • .prn
  • .ps
  • .psb
  • .psd
  • .pst
  • .ptx
  • .pub
  • .pwm
  • .pxr
  • .py
  • .qt
  • .r3d
  • .raf
  • .rar
  • .raw
  • .rdf
  • .rgbe
  • .rle
  • .rqy
  • .rss
  • .rtf
  • .rw2
  • .rwl
  • .safe
  • .sct
  • .sdpx
  • .shtm
  • .shtml
  • .slk
  • .sln
  • .sql
  • .sr2
  • .srf
  • .srw
  • .ssi
  • .st
  • .stm
  • .svg
  • .svgz
  • .swf
  • .tab
  • .tar
  • .tbb
  • .tbi
  • .tbk
  • .tdi
  • .tga
  • .thmx
  • .tif
  • .tiff
  • .tld
  • .torrent
  • .tpl
  • .txt
  • .u3d
  • .udl
  • .uxdc
  • .vb
  • .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
  • .xl
  • .xla
  • .xlam
  • .xlk
  • .xlm
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .xml
  • .xps
  • .xsd
  • .xsf
  • .xsl
  • .xslt
  • .xsn
  • .xtp
  • .xtp2
  • .xyze
  • .xz
  • .zip

It does the following:

  • 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 avoids encrypting files/directories with the following strings:
    • %Windows%
    • boot.ini
    • bootfont.bin
    • ntldr
    • ntdetect.com
    • io.sys
    • RETURN FILES.txt
    • Info.hta
    • {Malware Filename}.exe
  • It encrypts files in all fixed, remote and removable drives.

It 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}txxx@protonmail.com].xxx

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

  • %Application Data%\Info.hta Shows the following Ransom Note
  • %System%\Info.hta -> Detected as Ransom.HTML.CRYSIS.AA.note
  • %User Startup%\Info.hta -> Detected as Ransom.HTML.CRYSIS.AA.note
  • %ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup\Info.hta
  • {All Drives}\FILES ENCRYPTED.txt
  • %Desktop%\RETURN FILES.txt Shows the following Ransom note

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.228.04

FIRST VSAPI PATTERN DATE:

11 Jul 2019

VSAPI OPR PATTERN File:

15.229.00

VSAPI OPR PATTERN Date:

12 Jul 2019

Step 1

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 2

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 3

Restart in Safe Mode

[ Learn More ]

Step 4

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\CurrentVersion\Run
    • %System%\Info.hta = "mshta.exe "%System%\Info.hta""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • %Application Data%\Info.hta = "mshta.exe "%Application Data%\Info.hta""
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • %Application Data%\Info.hta = "mshta.exe "%Application Data%\Info.hta""
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • {Malware Filename} = "%System%\{Malware Filename}"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • {Malware Filename} = "%Application Data%\{Malware Filename}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {Malware Filename} = "%Application Data%\{Malware Filename}"

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.  
  • %Application Data%\Info.hta
  • %System%\Info.hta
  • %User Startup%\Info.hta
  • %All Users Profile%\Microsoft\Windows\Start Menu\Programs\Startup\Info.hta
  • {Public User Desktop}\RETURN FILES.txt
  • {All Drives}\RETURN FILES.txt
  • %Desktop%\RETURN FILES.txt

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.APHX. 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 8

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


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