RANSOM_CRYPREN.B

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.

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 and executes the following files:

• %User Profile%\32.exe

(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.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

• My_Program_Already_Present

Autostart Technique

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

• %User Startup%\3.lnk

(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.)

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Dropping Routine

This Trojan drops the following files:

• {Folder Path Visited}\help-decrypr-file.enc
  
• %User Profile%\3.png
  

Other Details

This Trojan displays the following message boxes:

It encrypts files with the following extensions:

• .bkp
• .blend
• .bpw
• .c
• .cdr
• .cdf
• .cdr3
• .cdr5
• .cdr4
• .cdr6
• .cdrw
• .cdx
• .ce1
• .ce2
• .cer
• .cfp
• .cgm
• .cib
• .cls
• .cmt
• .cpi
• .craw
• .crt
• .csh
• .css
• .csv
• .dac
• .db
• .db-journal
• .db3
• .dbf
• .dc2
• .dcr
• .dcs
• .ddd
• .ddoc
• .ddrw
• .der
• .design
• .dgc
• .djvu
• .dng
• .doc
• .docm
• .docx
• .dot
• .dotm
• .dotx
• .drf
• .drw
• .dwg
• .dxb
• .erbsql
• .erf
• .exf
• .fdb
• .ffd
• .fff
• .fh
• .fhd
• .fpx
• .fxg
• .gray
• .grey
• .gry
• .h
• .hbk
• .hpp
• .ibank
• .idb
• .ibz
• .idx
• .iiq
• .incpas
• .jpg
• .jpeg
• .js
• .kc2
• .kdbx
• .kdc
• .kpdx
• .lua
• .mdb
• .mdc
• .mef
• .mfw
• .mmw
• .moneywell
• .mos
• .mpg
• .mrw
• .myd
• .ndd
• .nef
• .nop
• .nrw
• .ns2
• .ns3
• .ns4
• .nsd
• .nsf
• .nsg
• .nsh
• .nwb
• .nx1
• .nx2
• .nyf
• .odb
• .odf
• .odg
• .odm
• .odp
• .ods
• .odt
• .orf
• .otg
• .oth
• .otp
• .ots
• .ott
• .p12
• .p7b
• .p7c
• .pat
• .pcd
• .pdf
• .pef
• .pem
• .pfx
• .php
• .pl
• .pot
• .potm
• .potx
• .ppam
• .pps
• .ppsm
• .ppsx
• .ppt
• .pptm
• .pptx
• .ps
• .psafe3
• .psd
• .ptx
• .ra2
• .raf
• .rar
• .raw
• .rdb
• .rtf
• .rwl
• .rw2
• .rwz
• .s3db
• .sas7bdat
• .sav
• .sdo
• .sd1
• .sda
• .sdf
• .sldm
• .sldx
• .sqlite
• .sqlite3
• .sqlitedb
• .sr2
• .srf
• .srw
• .st4
• .st5
• .st6
• .st7
• .st8
• .stc
• .std
• .sti
• .stw
• .stx
• .sxc
• .sxd
• .sxg
• .sxi
• .sxm
• .sxw
• .txt
• .wb2
• .x3f
• .xla
• .xlam
• .xll
• .xlm
• .3ds
• .3fr
• .3pr
• .7z
• .ab4
• .ac2
• .accdb
• .accde
• .accdr
• .accdt
• .acr
• .adb
• .agd1
• .ai
• .ait
• .al
• .apj
• .arw
• .asp
• .awg
• .backup
• .backupdb
• .bak
• .bdb
• .bgt
• .bik
• .xls
• .xlsx
• .xlsb
• .xlsm
• .xlt
• .xltm
• .xltx
• .xlw
• .xml
• .ycbcra
• .zip
• .JPG
• .JPEG
• .mp3

It renames encrypted files using the following names:

• {Original File name and Extension}.{BLOCKED}@INDIA.COM

NOTES:

This Trojan finds files to encrypt in the following drives:

• C:\
• D:\
• E:\
• F:\
• G:\
• H:\
• T:\