Ransom_CRYPWALL.TZ

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies registry entries to disable various system services. This action prevents most of the system functions to be used.

It connects to certain websites to send and receive information. It deletes the initially executed copy of itself.

Arrival Details

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

• %System Root%\{random 8 characters}\{random 8 characters}.exe
• %Application Data%\{random 8 characters}.exe
• %User Startup%\{random 8 characters}.exe

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

It drops the following files:

• %User Startup%\HELP_DECRYPT.HTML
• %User Startup%\HELP_DECRYPT.PNG
• %User Startup%\HELP_DECRYPT.TXT
• %User Startup%\HELP_DECRYPT.URL

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

It drops and executes the following files:

• %Desktop%\HELP_DECRYPT.HTML
• %Desktop%\HELP_DECRYPT.PNG
• %Desktop%\HELP_DECRYPT.TXT
• %Desktop%\HELP_DECRYPT.URL

(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It adds the following processes:

• explorer.exe
• svchost.exe

It is injected into the following processes running in memory:

• created svchost.exe
• created explorer.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random 7 characters} = "%System Root%\{random 8 characters}\{random 8 characters}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random 8 characters} = "%Application Data%\{random 8 characters}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
*{random 6 characters} = "%System Root%\{random 8 characters}\{random 8 characters}.exe" (for Windows Vista and above only)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
*{random 7 characters} = "%Application Data%\{random 8 characters}.exe" (for Windows Vista and above only)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\{UID}

HKEY_CURRENT_USER\Software\{UID}\
{random key}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\{UID}
{random 2 characters} = "{contents of HELP_DECRYPT.URL}"

HKEY_CURRENT_USER\Software\{UID}
{random 2 characters} = "{contents of HELP_DECRYPT.TXT}"

HKEY_CURRENT_USER\Software\{UID}
{random 2 characters} = "{contents of HELP_DECRYPT.HTML}"

HKEY_CURRENT_USER\Software\{UID}
{random 2 characters} = "{RSA PUBLIC KEY}"

HKEY_CURRENT_USER\Software\{UID}\
{random key}
{Path and file of encrypted file} = "{hex values}"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SystemRestore
DisableSR = "1"

(Note: The default value data of the said registry entry is 0.)

It modifies registry entries to disable the following system services:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\BITS
Start = "4"

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wscsvc
Start = "4"

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ERSvc
Start = "4"

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuauserv
Start = "4"

(Note: The default value data of the said registry entry is 2.)

Information Theft

This Trojan gathers the following data:

• Unique Identifier (UID)
• Machine Screenshot

Other Details

This Trojan connects to the following URL(s) to get the affected system's IP address:

• http://ip-addr.es
• http://myexternalip.com/raw
• http://curlmyip.com

It connects to the following website to send and receive information:

• http://{BLOCKED}cc.org/4.php
• http://{BLOCKED}ranslation.com/media/editors/tinymce/jscripts/tiny_mce/plugins/lists/2.php
• http://{BLOCKED}ogroup.com/plugins/content/jw_sig/jw_sig/includes/js/jquery_fancybox/5.php
• http://{BLOCKED}rning.com/amisonline05062015/amis4/permaswagefr/Resources/SPR-Pool/SPR0522/Resources/4.php
• http://{BLOCKED}atereqpt.com/media/editors/tinymce/jscripts/tiny_mce/plugins/noneditable/3.php
• http://{BLOCKED}ll.net/Old%20files/wp-content/plugins/ml-slider/assets/colorbox/images/ie6/1.php
• http://{BLOCKED}pplyonline.com/plugins/system/gantry/overrides/3.0/2.5/com_weblinks/5.php
• http://{BLOCKED}irtransplantbangalore.com/media/editors/tinymce/jscripts/tiny_mce/plugins/iespell/4.php
• http://{BLOCKED}naforestchildcare.com/plugins/system/gantry/overrides/3.0/2.5/mod_stats/5.php
• http://{BLOCKED}.eu/wp-content/themes/decoy2/redux-framework/ReduxCore/inc/fields/info/2.php
• http://{BLOCKED}lcarolinasports.com/plugins/system/gantry/overrides/3.0/2.5/mod_weblinks/2.php
• http://{BLOCKED}rbbom.com.br/wp-content/plugins/revslider/css/jui/old/images/5.php
• http://{BLOCKED}irbahrain.com/plugins/content/jw_sig/jw_sig/tmpl/Classic/images/2.php
• http://dev.{BLOCKED}a.pl/1.php
• http://{BLOCKED}s.com.br/wp-content/cache/db/000000/all/225/521/5.php
• http://{BLOCKED}dglassbh.com/media/editors/tinymce/jscripts/tiny_mce/plugins/layer/3.php
• http://{BLOCKED}dental.com/media/editors/tinymce/jscripts/tiny_mce/plugins/bbcode/3.php
• http://{BLOCKED}ster.info/components/com_fabrik/views/package/tmpl/module/images/1.php
• http://{BLOCKED}rain.com/media/editors/tinymce/jscripts/tiny_mce/plugins/save/4.php
• http://{BLOCKED}rim.fr/components/com_jce/editor/tiny_mce/plugins/visualblocks/css/2.php
• http://{BLOCKED}t.ru/components/com_jce/editor/libraries/views/browser/tmpl/4.php
• http://{BLOCKED}haccess.com/components/com_comprofiler/plugin/templates/winclassic/images/cluetip/5.php
• http://{BLOCKED}atent.net/en/wp-content/themes/u-design/scripts/superfish-menu/images/4.php
• http://konrad.{BLOCKED}ak.eu/1.php
• http://{BLOCKED}ent-retro.ru/plugins/editors/tinymce/jscripts/tiny_mce/plugins/fullscreen/3.php
• http://{BLOCKED}abrides.org.uk/wp-content/plugins/wpclef/assets/src/sass/neat/5.php
• http://{BLOCKED}nsfamilyhair.com/components/com_jce/editor/extensions/popups/window/tmpl/1.php
• http://{BLOCKED}tex.ru/templates/yoo_vida/warp/systems/joomla/language/sv-SE/5.php
• http://{BLOCKED}-krepezha.ru/administrator/components/com_chronoforms/js/tiny_mce/plugins/autolink/2.php
• http://{BLOCKED}osite.dk/wp-content/plugins/js_composer/assets/lib/prettyphoto/images/1.php
• http://{BLOCKED}a.{BLOCKED}il.net/2.php
• http://{BLOCKED}a.be/wp-content/plugins/sitepress-multilingual-cms/inc/installer/locale/orig/3.php
• http://{BLOCKED}ebaudin.com/wp-content/themes/skylab/option-tree/assets/images/layout/2.php
• http://{BLOCKED}environmental.com/components/com_jce/editor/extensions/popups/jcemediabox/css/3.php
• http://{BLOCKED}man.com/wp-content/plugins/wordpress-seo/vendor/yoast/license-manager/views/1.php
• http://{BLOCKED}t.com/media/editors/tinymce/jscripts/tiny_mce/plugins/spellchecker/5.php
• http://{BLOCKED}ct.com/wp-content/plugins/jetpack/modules/widget-visibility/widget-conditions/rtl/3.php
• http://{BLOCKED}mix.sk/wp-content/themes/Impreza/vendor/meta-box/css/jqueryui/1.php
• http://{BLOCKED}ak.eu/2.php
• http://{BLOCKED}byteits.com/media/coalawebsocial/plugins/quickicon/sociallinks/images/icons/4.php
• http://{BLOCKED}icaven.com/templates/yoo_salt/warp/systems/joomla/language/sr-YU/1.php
• http://{BLOCKED}bahrain.com/media/editors/tinymce/jscripts/tiny_mce/plugins/layer/4.php
• http://{BLOCKED}products.com/components/com_rokgallery/templates/gallery/grid-3col/light/images/1.php

It encrypts files with the following extensions:

• ce2
• cer
• cfp
• cgm
• cib
• class
• cls
• cmt
• cpi
• cpp
• cr2
• craw
• crt
• crw
• cs
• csh
• csl
• csv
• dac
• db
• db3
• dbf
• db-journal
• dc2
• dcr
• dcs
• ddd
• ddoc
• ddrw
• dds
• der
• des
• design
• dgc
• djvu
• dng
• doc
• docm
• docx
• dot
• dotm
• dotx
• drf
• drw
• dtd
• dwg
• dxb
• dxf
• dxg
• eml
• eps
• erbsql
• erf
• exf
• fdb
• ffd
• fff
• fh
• fhd
• fla
• flac
• flv
• fpx
• fxg
• gray
• grey
• gry
• h
• hbk
• hpp
• ibank
• ibd
• ibz
• idx
• iif
• iiq
• incpas
• indd
• java
• jpe
• jpeg
• jpg
• kc2
• kdbx
• kdc
• key
• kpdx
• lua
• m
• m4v
• max
• mdb
• mdc
• mdf
• mef
• mfw
• mmw
• moneywell
• mos
• mov
• mp3
• mp4
• mpg
• mrw
• msg
• myd
• nd
• ndd
• nef
• nk2
• nop
• nrw
• ns2
• ns3
• ns4
• nsd
• nsf
• nsg
• nsh
• nwb
• nx2
• nxl
• nyf
• oab
• obj
• odb
• odc
• odf
• odg
• odm
• odp
• ods
• odt
• oil
• orf
• ost
• otg
• oth
• otp
• ots
• ott
• p12
• p7b
• p7c
• pab
• pages
• pas
• pat
• pcd
• pct
• pdb
• pdd
• pdf
• pef
• pem
• pfx
• php
• pl
• plc
• pot
• potm
• potx
• ppam
• pps
• ppsm
• ppsx
• ppt
• pptm
• pptx
• prf
• ps
• psafe3
• psd
• pspimage
• pst
• ptx
• py
• qba
• qbb
• qbm
• qbr
• qbw
• qbx
• qby
• r3d
• raf
• rar
• rat
• raw
• rdb
• rm
• rtf
• rw2
• rwl
• rwz
• s3db
• sas7bdat
• say
• sd0
• sda
• sdf
• sldm
• sldx
• sql
• sqlite
• sqlite3
• sqlitedb
• sr2
• srf
• srt
• srw
• st4
• st5
• st6
• st7
• st8
• std
• sti
• stw
• stx
• svg
• swf
• sxc
• sxd
• sxg
• sxi
• sxi
• sxm
• sxw
• tex
• tga
• thm
• tlg
• txt
• vob
• wallet
• wav
• wb2
• wmv
• wpd
• wps
• x11
• x3f
• xis
• xla
• xlam
• xlk
• xlm
• xlr
• xls
• xlsb
• xlsm
• xlsx
• xlt
• xltm
• xltx
• xlw
• ycbcra
• 3dm
• 3ds
• 3fr
• 3g2
• 3gp
• 3pr
• 7z
• ab4
• accdb
• accde
• accdr
• accdt
• ach
• acr
• act
• adb
• ads
• agdl
• ai
• ait
• al
• apj
• arw
• asf
• asm
• asp
• asx
• avi
• awg
• back
• backup
• backupdb
• bak
• bank
• bay
• bdb
• bgt
• bik
• bkp
• blend
• bpw
• c
• cdf
• cdr
• cdr3
• cdr4
• cdr5
• cdr6
• cdrw
• cdx
• ce1
• yuv
• zip

It deletes the initially executed copy of itself

NOTES:

It avoids encrypting files inside the following directories:

• windows
• temp
• .
• ..
• cache
• Y@Cs
• uvOyR
• nvidia
• games
• packages

It deletes shadow copies by executing the following command:

• vssadmin.exe Delete Shadows /All /Quiet

It drops HELP_DECRYPT.HTML, HELP_DECRYPT.PNG, HELP_DECRYPT.TXT, and HELP_DECRYPT.URL to all folders where files are encrypted.

It opens the dropped ransom notes HELP_DECRYPT.TXT, HELP_DECRYPT.PNG and HELP_DECRYPT.HTML:

It demands payment for using decryption service: