RANSOM_KARO.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 websites to send and receive information.

It encrypts files with specific file extensions. It encrypts files found in specific folders. 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:

• %Application Data%\svchost.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%\aes

(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 creates the following folders:

• %User Temp%\Tor ← contains Tor browser components

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

• MyUniqueMutexName

Autostart Technique

This Ransomware drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

• %User Startup%\Notepad.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.)

Other System Modifications

This Ransomware sets the system's desktop wallpaper to the following image:

Download Routine

This Ransomware connects to the following URL(s) to download its component file(s):

• https://{BLOCKED}t.{BLOCKED}ject.org/torbrowser/7.0.1/tor-win32-0.3.0.8.zip (Tor Browser)
• http://{BLOCKED}4eayyxjc4j.onion/wall.png (Ransom Note Wallpaper)

It saves the files it downloads using the following names:

• %User Temp%\{5 random characters}.zip ← Tor Browser Package
• %User Temp%\{5 random characters}.jpg ← Ransom Note Wallpaper

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Other Details

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

• http://{BLOCKED}4eayyxjc4j.onion/control.php?uid={value}&uname={value}&os={value}&pcname={value}
• http://{BLOCKED}4eayyxjc4j.onion/controller.php?uid={value}&aes={value}
• http://{BLOCKED}4eayyxjc4j.onion/total.php?uid={value}&total={value}

It does the following:

• It checks for virtual environment by checking the presence of the following strings:
  • virtual
  • vmware
  • VirtualBox
  Once found, It will execute the following process before terminating:
  • %System%\cmd.exe /c PING -n 5 127.0.0.1 & del /f /q "%temp%\*.*
• It checks if the following module is loaded in its process as an anti-sandbox technique:
  • SbieDLL.dll
• It execute the following commands:
  • %System%\cmd.exe icacls %User Temp% /grant Everyone:F /T /C /Q (Grants Permission to %User Temp% for all Users)
  • %User Temp%\Tor\Microsoft.vshub.32.exe" -f .\torrc (Executes Tor Browser)
  • %System%\cmd.exe" /c taskkill.exe /f /im Microsoft.Exchange.*
  • %System%\cmd.exe" /c taskkill.exe /f /im MSExchange*
  • %System%\cmd.exe" /c taskkill.exe /f /im sqlserver.exe
  • %System%\cmd.exe" /c taskkill.exe /f /im sqlwriter.exe
  • %System%\cmd.exe" /c taskkill.exe /f /im mysqld.exe
  • %System%\cmd.exe /c taskkill.exe /f /im Microsoft.vshub.32.exe.*
  • %System%\cmd.exe /c PING -n 5 127.0.0.1 & del /f /q "%temp%\*.* (Deletes all files under %User Temp% directory
• The following are Tor Browser components installed by this ransomware:
  • %User Temp%\Tor\libeay32.dll
  • %User Temp%\Tor\libevent-2-0-5.dll
  • %User Temp%\Tor\libevent_core-2-0-5.dll
  • %User Temp%\Tor\libevent_extra-2-0-5.dll
  • %User Temp%\Tor\libgcc_s_sjlj-1.dll
  • %User Temp%\Tor\libssp-0.dll
  • %User Temp%\Tor\ssleay32.dll
  • %User Temp%\Tor\tor-gencert.exe
  • %User Temp%\Tor\Microsoft.vshub.32.exe -> (renamed from tor.exe)
  • %User Temp%\Tor\zlib1.dll
  • %User Temp%\Tor\torrc

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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
• .3dm
• .3ds
• .3fr
• .3g2
• .3gp
• .3gp2
• .3mm
• .3pr
• .7z
• .7zip
• .aac
• .ab4
• .abk
• .abw
• .ac3
• .accdb
• .accde
• .accdr
• .accdt
• .ace
• .ach
• .acr
• .act
• .adb
• .ade
• .adi
• .adp
• .adpb
• .adr
• .ads
• .adt
• .agdl
• .ai
• .aiff
• .aim
• .aip
• .ais
• .ait
• .al
• .amf
• .amr
• .amu
• .amx
• .amxx
• .ans
• .aoi
• .ap
• .ape
• .api
• .apj
• .arc
• .ari
• .arj
• .aro
• .arr
• .arw
• .asa
• .asc
• .ascx
• .ase
• .asf
• .ashx
• .asm
• .asmx
• .asp
• .aspx
• .asr
• .asx
• .avi
• .avs
• .awg
• .back
• .backup
• .backupdb
• .bak
• .bank
• .bay
• .bck
• .bdb
• .bdp
• .bdr
• .bgt
• .bib
• .bic
• .big
• .bik
• .bin
• .bkf
• .bkp
• .blend
• .blp
• .bmc
• .bmf
• .bml
• .bmp
• .boc
• .bp2
• .bp3
• .bpl
• .bpw
• .bsp
• .c
• .cag
• .cam
• .cap
• .car
• .cbr
• .cbz
• .cc
• .ccd
• .cch
• .cd
• .cdf
• .cdr
• .cdr3
• .cdr4
• .cdr5
• .cdr6
• .cdrw
• .cdx
• .ce1
• .ce2
• .cer
• .cfg
• .cgf
• .cgm
• .chk
• .cib
• .class
• .clr
• .cls
• .cms
• .cmt
• .cod
• .col
• .config
• .contact
• .cp
• .cpi
• .cpp
• .cr2
• .craw
• .crd
• .crt
• .crw
• .cs
• .csh
• .csi
• .csl
• .cso
• .css
• .csv
• .ctt
• .cty
• .cwf
• .dac
• .dal
• .dap
• .dat
• .db
• .db3
• .db_journal
• .dbb
• .dbf
• .dbx
• .dc2
• .dcp
• .dcr
• .dcs
• .dcu
• .ddc
• .ddcx
• .ddd
• .ddoc
• .ddrw
• .dds
• .dem
• .der
• .des
• .design
• .dev
• .dex
• .dgc
• .dic
• .dif
• .dii
• .dir
• .disk
• .dit
• .divx
• .diz
• .djvu
• .dmg
• .dng
• .dob
• .doc
• .docm
• .docx
• .dot
• .dotm
• .dotx
• .dox
• .dpk
• .dpl
• .dpr
• .drf
• .drw
• .dsk
• .dsp
• .dtd
• .dvd
• .dvi
• .dvx
• .dwg
• .dxb
• .dxe
• .dxf
• .dxg
• .edb
• .elf
• .eml
• .eps
• .eql
• .erbsql
• .erf
• .err
• .euc
• .evo
• .ex
• .exf
• .exif
• .f90
• .faq
• .fcd
• .fdb
• .fdr
• .fds
• .ff
• .ffd
• .fff
• .fh
• .fhd
• .fla
• .flac
• .flf
• .flp
• .flv
• .flvv
• .for
• .fpp
• .fpx
• .fxg
• .gam
• .gif
• .gray
• .grey
• .grf
• .groups
• .gry
• .gthr
• .gz
• .gzig
• .h
• .h3m
• .h4r
• .hbk
• .hdd
• .hpp
• .htm
• .html
• .ibank
• .ibd
• .ibz
• .idx
• .iif
• .iiq
• .img
• .incpas
• .indd
• .ink
• .ipa
• .isu
• .isz
• .itdb
• .itl
• .iwd
• .jar
• .jav
• .java
• .jc
• .jfif
• .jgz
• .jif
• .jiff
• .jnt
• .jpc
• .jpe
• .jpeg
• .jpf
• .jpg
• .jpw
• .js
• .kc2
• .kdbx
• .kdc
• .key
• .kmz
• .kpdx
• .kwd
• .kwm
• .laccdb
• .lbi
• .lcd
• .lcf
• .ldb
• .ldf
• .lgp
• .lit
• .log
• .lp2
• .ltm
• .ltr
• .lua
• .lvl
• .m
• .m2ts
• .m3u
• .m4p
• .m4v
• .mag
• .man
• .map
• .mapimail
• .max
• .mbox
• .mbx
• .mcd
• .md
• .md3
• .mdb
• .mdc
• .mdf
• .mdl
• .mdn
• .mds
• .mef
• .mfw
• .mic
• .mid
• .mip
• .mkv
• .mlb
• .mlx
• .mmw
• .mny
• .mod
• .moneywell
• .mos
• .mov
• .moz
• .mp3
• .mp4
• .mpeg
• .mpg
• .mrw
• .msg
• .msp
• .mxp
• .myd
• .nav
• .ncd
• .nd
• .ndd
• .ndf
• .nds
• .nef
• .nfo
• .nk2
• .nop
• .now
• .nrg
• .nri
• .nrw
• .ns2
• .ns3
• .ns4
• .nsd
• .nsf
• .nsg
• .nsh
• .nvram
• .nwb
• .nx2
• .nxl
• .nyf
• .oab
• .obj
• .odb
• .odc
• .odf
• .odg
• .odi
• .odm
• .odp
• .ods
• .odt
• .oft
• .oga
• .ogg
• .oil
• .opf
• .orf
• .ost
• .otg
• .oth
• .otp
• .ots
• .ott
• .owl
• .oxt
• .p12
• .p7b
• .p7c
• .pab
• .pages
• .pak
• .pas
• .pat
• .pbf
• .pbp
• .pbs
• .pcd
• .pct
• .pcv
• .pdb
• .pdd
• .pdf
• .pef
• .pem
• .pfx
• .php
• .pif
• .pkb
• .pkh
• .pl
• .plc
• .pli
• .plus_muhd
• .pm
• .png
• .pot
• .potm
• .potx
• .ppam
• .ppd
• .ppf
• .pps
• .ppsm
• .ppsx
• .ppt
• .pptm
• .pptx
• .prc
• .prf
• .prt
• .ps
• .psa
• .psafe3
• .psd
• .pspimage
• .py
• .pst
• .ptx
• .puz
• .pwf
• .pwi
• .pwm
• .pxp
• .py
• .qba
• .qbb
• .qbm
• .qbr
• .qbw
• .qbx
• .qby
• .qcow
• .qcow2
• .qdf
• .qed
• .qel
• .qif
• .qpx
• .qtq
• .qtr
• .r3d
• .ra
• .raf
• .rar
• .rat
• .raw
• .rdb
• .res
• .rev
• .rgn
• .rm
• .rng
• .rrt
• .rsrc
• .rsw
• .rte
• .rtf
• .rts
• .rtx
• .rum
• .run
• .rv
• .rvt
• .rw2
• .rwl
• .rwz
• .s3db
• .sad
• .saf
• .safe
• .sas7bdat
• .sav
• .save
• .say
• .scm
• .scn
• .scx
• .sd0
• .sda
• .sdb
• .sdc
• .sdf
• .sdn
• .sds
• .sdt
• .sen
• .sfs
• .sfx
• .sh
• .shar
• .shr
• .shw
• .sldm
• .sldx
• .slt
• .snp
• .so
• .spr
• .sql
• .sqlite
• .sqlite3
• .sqlitedb
• .sqx
• .sr2
• .srf
• .srt
• .srw
• .ssa
• .st4
• .st5
• .st6
• .st7
• .st8
• .stc
• .std
• .sti
• .stm
• .stt
• .stw
• .stx
• .sud
• .svg
• .svi
• .svr
• .swd
• .swf
• .sxc
• .sxd
• .sxg
• .sxi
• .sxm
• .sxw
• .tar
• .tax2013
• .tax2014
• .tbz2
• .tch
• .tcx
• .tex
• .txt
• .text
• .tg
• .tga
• .thm
• .thmx
• .tif
• .tlg
• .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
• .vbox
• .vc
• .vcd
• .vdi
• .vdo
• .ver
• .vhd
• .vhdx
• .vmdk
• .vmf
• .vmsd
• .vmt
• .vmx
• .vmxf
• .vob
• .vsi
• .vtf
• .w3g
• .w3x
• .wab
• .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
• .x11
• .x3f
• .xis
• .xl
• .xla
• .xlam
• .xlc
• .xlk
• .xll
• .xlm
• .xlr
• .xls
• .xlsb
• .xlsm
• .xlsx
• .xlt
• .xltm
• .xltx
• .xlv
• .xlw
• .xlwx
• .xml
• .xpi
• .xpt
• .xvid
• .xwd
• .yab
• .ycbcra
• .yps
• .yuv
• .z02
• .z04
• .zap
• .zip
• .zipx
• .zoo
• .saz
• .tlp

It encrypts files found in the following folders:

• All folders under All Fixed Drives Except %System Root%
• %Desktop%
• %User Profile%\Pictures
• %User Profile%\Music
• %User Profile%\Documents

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %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.. %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 appends the following extension to the file name of the encrypted files:

• .ipygh

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

• %Desktop%\ReadMe.html

(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.)

NOTES:
The ransom note ReadMe.html contains the following: