RANSOM_FROZRLOCK.A

This Ransomware 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 URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats. As of this writing, the said sites are inaccessible.

It encrypts files with specific file extensions. It drops files as ransom note.

Arrival Details

This Ransomware 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 Ransomware drops the following copies of itself into the affected system and executes them:

• %Application Data%\UpdateServices.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:

• %Application Data%\file_list.txt
• %Application Data%\Locker_ID.txt
• %Application Data%\Pub_Key.xml

(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 leaves text files that serve as ransom notes containing the following:

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

• MutexToEnsureThatOnlyASingleInstanceIsRunningAsAdmin
• MutexToEnsureThatOnlyASingleInstanceIsRunningAsUser

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
UpdateSrevices = %Application Data%\UpdateServices.exe

Download Routine

This Ransomware connects to the following malicious URLs:

• http://voh2in67mks5uygu.{BLOCKED}web.gq/receiver.php
• http://voh2in67mks5uygu.{BLOCKED}b.ga/receiver.php
• http://voh2in67mks5uygu.{BLOCKED}b.gq/receiver.php
• http://voh2in67mks5uygu.{BLOCKED}b.ml/receiver.php
• http://voh2in67mks5uygu.{BLOCKED}b.tk/receiver.php

As of this writing, the said sites are inaccessible.

Other Details

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

• http://icanhazip.com/

It does the following:

• Executes the following commands to delete itself and its drop copy:
  
  • cmd.exe /C choice /C Y /N /D Y /T 3 & Del {malware path}.exe
  • cmd.exe /C choice /C Y /N /D Y /T 3 & Del %Application Data%\UpdateServices.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.)

Ransomware Routine

This Ransomware encrypts files with the following extensions:

• .1cd
• .3d
• .3d4
• .3df8
• .3fr
• .3g2
• .3gp
• .3gp2
• .3mm
• .7z
• .aac
• .abk
• .abw
• .ac3
• .accdb
• .ace
• .act
• .ade
• .adi
• .adpb
• .adr
• .adt
• .ai
• .aim
• .aip
• .ais
• .amf
• .amr
• .amu
• .amx
• .amxx
• .ans
• .ap
• .ape
• .api
• .arc
• .ari
• .arj
• .aro
• .arr
• .arw
• .asa
• .asc
• .ascx
• .ase
• .asf
• .ashx
• .asmx
• .asp
• .asr
• .avi
• .avs
• .bak
• .bay
• .bck
• .bdp
• .bdr
• .bib
• .bic
• .big
• .bik
• .bkf
• .blp
• .bmc
• .bmf
• .bml
• .bmp
• .boc
• .bp2
• .bp3
• .bpl
• .bsp
• .cag
• .cam
• .cap
• .car
• .cbr
• .cbz
• .cc
• .ccd
• .cch
• .cd
• .cdr
• .cer
• .cfg
• .cgf
• .chk
• .clr
• .cms
• .cod
• .col
• .cp
• .cpp
• .cr2
• .crd
• .crt
• .crw
• .cs
• .csi
• .cso
• .ctt
• .cty
• .cwf
• .dal
• .dap
• .dbb
• .dbf
• .dbx
• .dcp
• .dcr
• .dcu
• .ddc
• .ddcx
• .dem
• .der
• .dev
• .dex
• .dic
• .dif
• .dii
• .dir
• .disk
• .divx
• .diz
• .djvu
• .dmg
• .dng
• .dob
• .doc
• .docm
• .docx
• .dot
• .dotm
• .dotx
• .dox
• .dpk
• .dpl
• .dpr
• .dsk
• .dsp
• .dvd
• .dvi
• .dvx
• .dwg
• .dxe
• .dxf
• .dxg
• .elf
• .eps
• .eql
• .erf
• .err
• .euc
• .evo
• .ex
• .exif
• .f90
• .faq
• .fcd
• .fdr
• .fds
• .ff
• .fla
• .flp
• .flv
• .for
• .fpp
• .gam
• .gif
• .grf
• .gthr
• .gz
• .gzig
• .h3m
• .h4r
• .htm
• .html
• .hwp
• .idx
• .img
• .indd
• .ink
• .ipa
• .isu
• .isz
• .itdb
• .itl
• .iwd
• .jar
• .jav
• .java
• .jc
• .jfif
• .jgz
• .jif
• .jiff
• .jpc
• .jpeg
• .jpf
• .jpg
• .jpw
• .js
• .kdc
• .kmz
• .kwd
• .lbi
• .lcd
• .lcf
• .ldb
• .lgp
• .log
• .log
• .lp2
• .ltm
• .ltr
• .lvl
• .mag
• .map
• .max
• .mbox
• .mbx
• .mcd
• .md3
• .mdb
• .mdf
• .mdl
• .mdn
• .mds
• .mef
• .meta
• .mic
• .mip
• .mkv
• .mlx
• .mod
• .moz
• .mp3
• .mp4
• .mpeg
• .mpg
• .mrw
• .msg
• .msp
• .mxp
• .nav
• .ncd
• .nds
• .nef
• .nfo
• .now
• .nrg
• .nri
• .nrw
• .odb
• .odc
• .odf
• .odi
• .odm
• .odp
• .ods
• .odt
• .oft
• .oga
• .ogg
• .opf
• .orf
• .owl
• .oxt
• .p12
• .p7b
• .p7c
• .pab
• .pak
• .pbf
• .pbp
• .pbs
• .pcv
• .pdd
• .pdf
• .pef
• .pem
• .pfx
• .php
• .pkb
• .pkh
• .pl
• .plc
• .pli
• .pm
• .png
• .pot
• .potm
• .potx
• .ppd
• .ppf
• .pps
• .ppsm
• .ppsx
• .ppt
• .pptm
• .pptx
• .prc
• .prt
• .psa
• .psd
• .pst
• .ptx
• .puz
• .pwf
• .pwi
• .pxp
• .qbb
• .qdf
• .qel
• .qif
• .qpx
• .qtq
• .qtr
• .r3d
• .ra
• .raf
• .rar
• .raw
• .res
• .rev
• .rgn
• .rng
• .rrt
• .rsrc
• .rsw
• .rte
• .rtf
• .rts
• .rtx
• .rum
• .run
• .rv
• .rw2
• .rwl
• .sad
• .saf
• .sav
• .scm
• .scn
• .scx
• .sdb
• .sdc
• .sdn
• .sds
• .sdt
• .sen
• .sfs
• .sfx
• .sh
• .shar
• .shr
• .shw
• .slt
• .snp
• .so
• .spr
• .sql
• .sqx
• .sr2
• .srf
• .srt
• .srw
• .ssa
• .std
• .stt
• .stx
• .sud
• .svi
• .svr
• .swd
• .swf
• .tar
• .tax2013
• .tax2014
• .tbz2
• .tch
• .tcx
• .text
• .tg
• .thmx
• .tif
• .tlz
• .tpu
• .tpx
• .trp
• .tu
• .tur
• .txd
• .txf
• .txt
• .uax
• .udf
• .umx
• .unr
• .unx
• .uop
• .upoi
• .url
• .usa
• .usx
• .ut2
• .ut3
• .utc
• .utx
• .uvx
• .uxx
• .val
• .vc
• .vcd
• .vdo
• .ver
• .vhd
• .vmf
• .vmt
• .vsi
• .vtf
• .w3g
• .w3x
• .wad
• .wallet
• .war
• .wav
• .wave
• .waw
• .wb2
• .wbk
• .wdgt
• .wks
• .wm
• .wma
• .wmd
• .wmdb
• .wmmp
• .wmv
• .wmx
• .wow
• .wpd
• .wpk
• .wpl
• .wps
• .wsh
• .wtd
• .wtf
• .wvx
• .x3f
• .xl
• .xla
• .xlam
• .xlc
• .xlk
• .xll
• .xlm
• .xlr
• .xls
• .xlsb
• .xlsm
• .xlsx
• .xltx
• .xlv
• .xlwx
• .xpi
• .xpt
• .xvid
• .xwd
• .yab
• .yps
• .z02
• .z04
• .zap
• .zip
• .zipx
• .zoo

It avoids encrypting files found in the following folders:

• "WindowsApps"
• "WinSxS"
• "System32"
• "Microsoft.NET"
• "SysWOW64"
• "SystemApps"

It drops the following file(s) as ransom note:

• %Desktop%\READ_ME.txt

(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.)