Ransom.Win32.CRYSIS.APHY

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.

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:

• mode con cp select=1251
• 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_99UUW6A
• Global\syncronize_99UUW6U

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

(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).)

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}k@protonmail.com].html

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

• %Desktop%\RETURN FILES.txt
• {Encrypted Drives}\RETURN FILES.txt
• %System%\Info.hta
• %User Startup%\Info.hta
• %ProgramData%\Microsoft\Windows\Start Menu\Programs\Startup\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).. %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 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).. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

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

NOTES:
Info.hta displays the following window: