TROJ_CRYPWALL.TH

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 the Internet Explorer Zone Settings.

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 and executes them:

• %Application Data%\{random}.exe

(Note: %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.)

It drops the following files:

• HELP_RESTORE_FILES_{random}.html
• HELP_RESTORE_FILES_{random}.txt

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random characters} = "%Application Data%\{random}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\{random characters}
data = {DATA}

HKEY_CURRENT_USER\Software\msys
ID = {DATA}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLinkedConnections = 1

Process Termination

This Trojan terminates processes or services that contain any of the following strings if found running in the affected system's memory:

• taskmgr
• procexp
• regedit
• msconfig
• cmd.exe

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Other Details

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

• ipinfo.io/ip

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

• http://{BLOCKED}4jksfds.sd5okr8mdfe4l.com/img.php
• http://vnrue854n3weo.{BLOCKED}sdf73a.com
• https://{BLOCKED}p62kz4nzx.tor2web.blutmagie.de

It encrypts files with the following extensions:

• sql
• mp4
• 7z
• rar
• m4a
• wma
• avi
• wmv
• csv
• d3dbsp
• zip
• sie
• sum
• ibank
• t13
• t12
• qdf
• gdb
• tax
• pkpass
• bc6
• bc7
• bkp
• qic
• bkf
• sidn
• sidd
• mdd
• ata
• itl
• itdb
• icxs
• hvpl
• hplg
• hkdbmdbackup
• syncdb
• gho
• cas
• svg
• map
• wmo
• itm
• sb
• fos
• mov
• vdf
• ztmp
• sis
• sid
• ncf
• menu
• layout
• dmp
• blob
• esm
• vcf
• vtf
• dazip
• fpk
• mlx
• kf
• iwd
• vpk
• tor
• psk
• rim
• w3x
• fsh
• ntl
• arch00
• lvl
• snx
• cfr
• ff
• vpp_pc
• lrf
• m2
• mcmeta
• vfs0
• mpqge
• kdb
• db0
• db
• rofl
• hkx
• bar
• upk
• das
• iwi
• litemod
• asset
• forge
• ltx
• bsa
• apk
• re4
• sav
• lbf
• slm
• bik
• epk
• rgss3a
• pak
• big
• unity3d
• wotreplay
• xxx
• desc
• py
• m3u
• flv
• js
• css
• rb
• png
• jpeg
• txt
• p7c
• p7b
• p12
• pfx
• pem
• crt
• cer
• der
• x3f
• srw
• pef
• ptx
• r3d
• rw2
• rwl
• raw
• raf
• orf
• nrw
• mrwref
• mef
• erf
• kdc
• dcr
• cr2
• crw
• bay
• sr2
• srf
• arw
• 3fr
• dng
• jpe
• jpg
• cdr
• indd
• ai
• eps
• pdf
• pdd
• psd
• dbf
• mdf
• wb2
• rtf
• wpd
• dxg
• xf
• dwg
• pst
• accdb
• mdb
• pptm
• pptx
• ppt
• xlk
• xlsb
• xlsm
• xlsx
• xls
• wps
• docm
• docx
• doc
• odb
• odc
• odm
• odp
• ods
• odt

It renames encrypted files using the following names:

• {original filename}.{ext}.zzz

It deletes the initially executed copy of itself