RANSOM_CRYPTESLA.GL

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 does not have any propagation routine.

It does not have any backdoor routine.

It modifies the Internet Explorer Zone Settings.

It connects to certain websites to send and receive information. It deletes itself after execution. It gathers information and reports it to its servers.

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%\wsmprovhost.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.)

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
FIX2-{random string} = "%System%\cmd.exe /c start "" "%Application Data%\wsmprovhost.exe""

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Axronics

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnabledLinkConnections = "1"

HKEY_CURRENT_USER\Software\Axronics
new_dataq = "{encrypted data}"

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Dropping Routine

This Trojan drops the following files:

• %User Profile%\Documents\storage_data
• %User Profile%\Documents\+recover+file.txt
• %Desktop%\{RecOveR}-{5 random characters}.Htm
• %Desktop%\{RecOveR}-{5 random characters}.Txt
• %Desktop%\{RecOveR}-{5 random characters}.Png

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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.)

Other Details

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

• http://{BLOCKED}d.com/binfile.php
• http://{BLOCKED}inogames.org/binfile.php
• http://{BLOCKED}rg-share.com/wp-content/plugins/contact-form-7/includes/js/jquery-ui/themes/smoothness/images/binfile.php
• http://{BLOCKED}flooring.com/wp-content/themese/sketch/binfile.php
• http://{BLOCKED}sundaytv.com/wp-content/themese/sketch/binfile.php
• http://{BLOCKED}esact.com/wp-content/themese/sketch/binfile.php

It encrypts files with the following extensions:

• .pif
• .com
• .bat
• .cmd
• .lnkimage
• .vfolder
• .zip
• .dvr-ms
• .wvx
• .wmx
• .wmv
• .wm
• .mpv2
• .mpg
• .mpeg
• .mpe
• .mpa
• .mp2v
• .mp2
• .m1v
• .IVF
• .asx
• .asf
• .avi
• .wax
• .snd
• .rmi
• .m3u
• .au
• .aiff
• .aifc
• .aif
• .midi
• .mid
• .wma
• .wav
• .mp3
• .wmf
• .tiff
• .tif
• .rle
• .png
• .jpeg
• .jpe
• .jpg
• .jfif
• .gif
• .emf
• .dib
• .wsh
• .wsf
• .wsc
• .ws
• .vsw
• .vst
• .vss
• .vsmacros
• .vbs
• .vbe
• .vb
• .shs
• .shb
• .sct
• .scr
• .scf
• .reg
• .pst
• .prg
• .prf
• .pl
• .pif
• .pcd
• .ops
• .mst
• .msp
• .mshxml
• .msh
• .msc
• .mdz
• .mdw
• .mdt
• .mde
• .mdb
• .mda
• .mcf
• .maw
• .mav
• .mau
• .mat
• .mas
• .mar
• .maq
• .mam
• .mag
• .maf
• .mad
• .lnk
• .ksh
• .jse
• .js
• .its
• .isp
• .ins
• .inf
• .hlp
• .grp
• .gadget
• .fxp
• .exe
• .csh
• .crt
• .cpl
• .cmd
• .chm
• .cer
• .bat
• .bas
• .app
• .adp
• .ade
• .xbap
• .xps
• .pdf
• .pot
• .hta
• .xlt
• .pps
• .xlw
• .dot
• .rtf
• .ppt
• .xls
• .doc
• .xml
• .hta
• .docx
• .mrwref
• .indd
• .rofl
• .mpqge
• .vfs0
• .mcmeta
• .vpp_pc
• .arch00
• .itdb
• .mddata
• .sidd
• .sidn
• .pkpass
• .ibank
• .dazip
• .blob
• .layout
• .menu
• .ztmp
• .syncdb
• .mdbackup
• .hkdb
• .hplg
• .hvpl
• .icxs
• .docm
• .xlsx
• .xlsm
• .xlsb
• .pptx
• .pptm
• .accdb
• .jpeg
• .desc
• .litesql
• wallet
• .rgss3a
• .forge
• .asset
• .litemod
• .d3dbsp
• .tiff
• .txt
• .bak

It sets the attributes of the following file(s) to Hidden and System:

• {dropped copy of itself}

It does the following:

• It deletes shadow copies by executing the following command:
  • %System%\wbem\WMIC.exe" shadowcopy delete /nointeractive
• It terminates processes containing the following strings:
  • taskmg <- Task Manager
  • procex <- Process Explorer
  • regedi <- Regedit
  • msconfi <- MS Config
• It avoids encrypting files with the following strings:
  • recove
• It encrypts files in all fixed, removable, and network drives and shares
• It drops {RecOveR}-{5 random characters}.Htm, {RecOveR}-{5 random characters}.Txt, {RecOveR}-{5 random characters}.Png to the folders where it tries to encrypt files
• It avoids encrypting files from the following directories:
  • Windows
  • Program Files
• It does not append extensions to files it encrypted

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It deletes itself after execution.

It gathers the following information and reports it to its servers:

• Infection status
• Bitcoin address
• Total size of encrypted files
• Malware version
• OS information
• Installation ID

NOTES:

This ransomware displays the following:

It does not have rootkit capabilities.

It does not exploit any vulnerability.