RANSOM_CRYPAURA.F

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It connects to certain websites to send and receive information. It deletes itself after execution.

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 files:

• %Application Data%\recovery.bmp - ransom message
• %Start Menu%\Programs\Startup\recovery.bmp - ransom message (for Windows Vista and higher)
• %User Startup%\recovery.bmp - ransom message (for Windows XP and lower)

(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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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 and executes the following files:

• {malware path}\cleen.bat - this will be deleted together with the inittally executed copy of the malware

Autostart Technique

This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

• %Start Menu%\Programs\Startup\{malware file name}.exe - for Windows Vista and higher
• %User Startup%\{malware file name}.exe - for Windows XP and lower

(Note: %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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.)

Other System Modifications

This Trojan changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"

(Note: The default value data of the said registry entry is {user preference}.)

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%Application Data%\recovery.bmp"

(Note: The default value data of the said registry entry is {user preference}.)

It sets the system's desktop wallpaper to the following image:

Information Theft

This Trojan gathers the following data:

• Computer name
• Machine GUID

Other Details

This Trojan connects to the following website to send and receive information:

• http://{BLOCKED}ma.lt/script.php

It encrypts files with the following extensions:

• .jpg
• .jpeg
• .doc
• .rtf
• .xls
• .zip
• .db3
• .rar
• .7z
• .3gp
• .cdr
• .raw
• .cpt
• .m2v
• .gzip
• .docx
• .pdf
• .odt
• .avi
• .mkv
• .ods
• .arj
• .cer
• .mdb
• .csv
• .mpeg
• .mov
• .ppt
• .orf
• .nrw
• .nx1
• .nbd
• .old
• .odb
• .odc
• .sldprt
• .wps
• .sldasm
• .sbs
• .p12
• .rx2
• .rwl
• .r3d
• .qic
• .odp
• .pz3
• .ptx
• .pst
• .txt
• .pptm
• .pef
• .x3f
• .tbl
• .tis
• .srw
• .srf
• .sr2
• .spf
• .sna
• .sn1
• .gho
• .gbk
• .iv2i
• .keystore
• .ldf
• .m3d
• .max
• .fbf
• .fdb
• .fbk
• .fbw
• .fbx
• .bak
• .bkf
• .bck
• .cf
• .erf
• .as4
• .asm
• .asvx
• .ate
• .bac
• .73b
• .a3d
• .abf
• .abk
• .accdb
• .113
• .xlsm
• .xlsk
• .xlsb
• .dwg
• .tib
• .pwm
• .wab
• .key
• .dt
• .ppsx
• .pptx
• .xlsx
• .1cd
• .dbf
• .mp3
• .prproj
• .ai
• .iso
• .ots
• .emlx
• .svg
• .aep
• .pps
• .flv
• .ofx
• .wmv
• .vob
• .swf
• .accdt
• .xml
• .qif
• .mp4
• .qt
• .xlr
• .db
• .pdb
• .sql
• .dxf
• .ost
• .pab
• .msg
• .QBW
• .QBB
• .QBM
• .OFX
• .QBO
• .QFX
• .QIF
• .epub
• .azw4
• .mobi
• .odf
• .djvu
• .fb2

It renames encrypted files using the following names:

• {original file name and extension}.id-{victim ID}_email1_sos@{BLOCKED}files.com_email2_zuza@{BLOCKED}mail.com_BitMessage_BM-NBemdRuEEVcaEgSenoQGVZpC9dm8Ycxn

It deletes itself after execution.

NOTES:

This Trojan traverses the following drives to encrypt files:

• c:\
• d:\
• e:\
• f:\
• g:\
• h:\
• i:\
• j:\
• k:\
• l:\
• m:\
• n:\
• o:\
• q:\
• r:\
• s:\
• t:\
• u:\
• v:\
• w:\
• x:\
• y:\
• z:\

However, it also avoids encrypting files located in the following folders:

• Program Files
• Program Files (x86)
• ProgramData
• System Volume Information
• Temp
• Windows