RANSOM_EMPER.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 connects to certain websites to send and receive information. 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:

• %System Root%\Users\Public\conlhost.exe (For Windows 7 and above)
• %All Users Profile%\conlhost.exe (For Windows XP and below)

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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 component file(s):

• For Windows XP and below:
  • %All Users Profile%\del.bat - deletes the initial copy of the malware
  • %All Users Profile%\time.e - contains installation date of the malware
  • %All Users Profile%\FILES_BACK.txt - ransom note
  • %All Users Profile%\testdecrypt - files which can be decrypted for free
  • %All Users Profile%\files - list of encrypted files
• For Windows 7 and above:
  • %System Root%\Users\Public\del.bat - deletes the initial copy of the malware
  • %System Root%\Users\Public\time.e - contains installation date of the malware
  • %System Root%\Users\Public\FILES_BACK.txt - ransom note
  • %System Root%\Users\Public\testdecrypt - files which can be decrypted for free
  • %System Root%\Users\Public\files - list of encrypted files

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

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
allkeeper = "%System Root%\Users\Public\conlhost.exe" (For Windows 7 and above)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
allkeeper = "%All Users Profile%\conlhost.exe" (For Windows XP and below)

Other System Modifications

This Trojan modifies the following file(s):

• It renames files and appends the extension .R5A or .R4A
• It encrypts files in all local drives and mapped network shares

It adds the following registry entries:

HKEY_CURRENT_USER\SOFTWARE
crypted = "1"

HKEY_CURRENT_USER\SOFTWARE
testdecrypt = "1"

HKEY_CURRENT_USER\SOFTWARE
Decrypt50 = "1"

Other Details

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

• http://{BLOCKED}3.{BLOCKED}2.153.154/jslkdfnroapi/index.php
• http://{BLOCKED}3.{BLOCKED}2.153.154/ldkmg545cp/LASkdnmgt.php?RIGHTS={privilege such as admin}&WIN={OS version}&WALLET={encrypted}&ID={unique ID}&UI={number}

It encrypts files with the following extensions:

• .dbf
• .arw
• .txt
• .doc
• .docm
• .docx
• .zip
• .rar
• .xlsx
• xls
• .xlsb
• .xlsm
• .jpg
• .jpe
• .jpeg
• .bmp
• .eql
• .sql
• .adp
• .mdf
• .mdb
• .odb
• .odm
• .odp
• .ods
• .pds
• .pdt
• pdf
• .cfu
• .mxl
• .epf
• .kdbx
• .erf
• .vrp
• .grs
• .geo
• .pff
• .mft
• .efd
• .rib
• .max
• .lwo
• .lws
• .obj
• .fbx
• .dgn
• .dwg
• .abs
• .adn
• .aft
• .ahd
• .alf
• .ask
• .awdb
• .azz
• .bdb
• .bib
• .bnd
• .bok
• .btr
• .bak
• .cdb
• .ckp
• .clkw
• .cma
• .crd
• .dad
• .daf
• .dbk
• .dbt
• .dbv
• .dbx
• .dcb
• .dct
• .dcx
• .ddl
• .dmo
• .dnc
• .dqy
• .dsk
• .dsn
• .dta
• .dtsx
• .dxl
• .eco
• .ecx
• .edb
• .emd
• .fcd
• .fic
• .fid
• .fil
• .fol
• .fpt
• .fzb
• .fzv
• .gdb
• .gwi
• .hdb
• .his
• .idc
• .ihx
• .itdb
• .itw
• .jtx
• .kdb
• .lgc
• .maq
• .mdn
• .mdt
• .mrg
• .mud
• .mwb
• .myd
• .ndf
• .nsf
• .nyf
• .oce
• .oqy
• .ora
• .orx
• .owc
• .owg
• .oyx
• .pan
• .pdb
• .pdm
• .phm
• .pnz
• .pth
• .pwa
• .qpx
• .qry
• .qvd
• .rctd
• .rdb
• .rpd
• .rsd
• .sbf
• .sdb
• .sdf
• .spq
• .sqb
• .stp
• .str
• .tcx
• .tdt
• .tmd
• .trm
• .udb
• .usr
• .vdb
• .vpd
• .wdb
• .wmdb
• .xdb
• .xld
• .xlgc
• .zdb
• .zdc
• .cdr
• .cdr3
• .ppt
• .pptx
• .abw
• .act
• .aim
• .ans
• .apt
• .asc
• .ase
• .aty
• .awp
• .awt
• .aww
• .bad
• .bbs
• .bdp
• .bdr
• .bean
• .bna
• .boc
• .btd
• .cnm
• .crwl
• .cyi
• .dca
• .dgs
• .diz
• .dne
• .docz
• .dot
• .dotm
• .dotx
• .dsv
• .dvi
• .eio
• .eit
• .emlx
• .epp
• .err
• .etf
• .etx
• .euc
• .faq
• .fbl
• .fcf
• .fdf
• .fdr
• .fds
• .fdt
• .fdx
• .fdxt
• .fes
• .fft
• .flr
• .fodt
• .gtp
• .frt
• .fwdn
• .fxc
• .gdoc
• .gio
• .gpn
• .gsd
• .gthr
• .hbk
• .hht
• .htc
• .hwp
• .idx
• .iil
• .ipf
• .jis
• .joe
• .jrtf
• .kes
• .klg
• .knt
• .kon
• .kwd
• .lbt
• .lis
• .lit
• .lnt
• .lrc
• .lst
• .ltr
• .ltx
• .lue
• .luf
• .lwp
• .lyt
• .lyx
• .man
• .map
• .mbox
• .mell
• .min
• .mnt
• .msg
• .mwp
• .nfo
• .njx
• .now
• .nzb
• .ocr
• .odo
• .odt
• .ofl
• .oft
• .ort
• .ott
• .pfs
• .pfx
• .pjt
• .prt
• .psw
• .pvj
• .pvm
• .pwi
• .pwr
• .qdl
• .rad
• .rft
• .ris
• .rng
• .rpt
• .rst
• .rtd
• .rtf
• .rtx
• .run
• .rzk
• .rzn
• .saf
• .sam
• .scc
• .scm
• .sct
• .scw
• .sdm
• .sdoc
• .sdw
• .sgm
• .sig
• .sla
• .sls
• .smf
• .sms
• .ssa
• .stw
• .sty
• .sub
• .sxg
• .sxw
• .tab
• .tdf
• .tex
• .text
• .thp
• .tlb
• .tmv
• .tmx
• .tpc
• .tvj
• .unx
• .uof
• .uot
• .upd
• .utf8
• .utxt
• .vct
• .vnt
• .wbk
• .wcf
• .wgz
• .wpa
• .wpd
• .wpl
• .wps
• .wpt
• .wpw
• .wri
• .wsc
• .wsd
• .wsh
• .wtx
• .xdl
• .xlf
• .xps
• .xwp
• .xyp
• .xyw
• .ybk
• .yml
• .zabw
• .abm
• .afx
• .agif
• .agp
• .aic
• .albm
• .apd
• .apm
• .apng
• .aps
• .apx
• .art
• .asw
• .bay
• .bmx
• .brk
• .brn
• .brt
• .bss
• .bti
• .cal
• .cals
• .can
• .cdc
• .cdg
• .cimg
• .cin
• .cit
• .colz
• .cpc
• .cpd
• .cpg
• .cps
• .cpx
• .dcr
• .dds
• .dgt
• .dib
• .djv
• .djvu
• .dmi
• .vue
• .dpx
• .wire
• .drz
• .dtw
• .dvl
• .ecw
• .eip
• .exr
• .fal
• .fax
• .fpos
• .fpx
• .gcdp
• .gfb
• .gfie
• .ggr
• .gif
• .gih
• .gim
• .spr
• .scad
• .gpd
• .gro
• .grob
• .hdp
• .hdr
• .hpi
• .icn
• .icon
• .icpr
• .iiq
• .info
• .ipx
• .itc2
• .iwi
• .jas
• .jbig
• .jbmp
• .jbr
• .jfif
• .jia
• .jng
• .jpg2
• .jps
• .jpx
• .jtf
• .jwl
• .jxr
• .kdc
• .kdi
• .kdk
• .kic
• .kpg
• .lbm
• .ljp
• .mac
• .mbm
• .mef
• .mnr
• .mos
• .mpf
• .mpo
• .mrxs
• .myl
• .ncr
• .nct
• .nlm
• .nrw
• .oci
• .omf
• .oplc
• .asy
• .cdmm
• .cdmt
• .cdmz
• .cdt
• .cgm
• .cmx
• .cnv
• .csy
• .cvg
• .cvi
• .cvs
• .cvx
• .cwt
• .cxf
• .dcs
• .ded
• .dhs
• .dpp
• .drw
• .dxb
• .dxf
• .egc
• .emf
• .eps
• .epsf
• .fif
• .fig
• .fmv
• .ftn
• .fxg
• .gem
• .glox
• .hpg
• .hpgl
• .hpl
• .idea
• .igt
• .igx
• .imd
• .ink
• .lmk
• .mgcb
• .mgmf
• .mgmt
• .mgmx
• .mgtx
• .mmat
• .mat
• .otg
• .ovp
• .ovr
• .pcs
• .pfv
• .plt
• .vrml
• .pobj
• .psid
• .rdl
• .scv
• .ssk
• .stn
• .svf
• .svgz
• .sxd
• .tlc
• .tne
• .ufr
• .vbr
• .vec
• .vml
• .vsd
• .vsdm
• .vsdx
• .vstm
• .stm
• .vstx
• .wpg
• .vsm
• .xar
• .yal
• .orf
• .ota
• .oti
• .ozb
• .ozj
• .ozt
• .pal
• .pano
• .pap
• .pbm
• .pcd
• .pdd
• .pef
• .pfi
• .pgf
• .pgm
• .pic
• .pict
• .pix
• .pjpg
• .pmg
• .pni
• .pnm
• .pntg
• .pop
• .ppm
• .prw
• .psdx
• .pse
• .psp
• .ptg
• .ptx
• .pvr
• .pxr
• .pza
• .pzp
• .pzs
• .qmg
• .ras
• .rcu
• .rgb
• .rgf
• .ric
• .riff
• .rix
• .rle
• .rli
• .rpf
• .rri
• .rsb
• .rsr
• .rwl
• .s2mv
• .sci
• .sep
• .sfc
• .sfw
• .skm
• .sld
• .sob
• .spa
• .spe
• .sph
• .spj
• .spp
• .srw
• .ste
• .sumo
• .sva
• .save
• .ssfn
• .tbn
• .tfc
• .thm
• .tjp
• .tpi
• .ufo
• .uga
• .vda
• .vff
• .vpe
• .vst
• .wbc
• .wbd
• .wbm
• .wbmp
• .wbz
• .wdp
• .webp
• .wpb
• .wpe
• .wvl
• .ysp
• .zif
• .cdr4
• .cdr6
• .cdrw
• .ddoc
• .css
• .pptm
• .raw
• .cpt
• .pcx
• .pdn
• .png
• .psd
• .tga
• .tiff
• .tif
• .xpm
• .sai
• .wmf
• .ani
• .flc
• .fli
• .mng
• .smil
• .svg
• .mobi
• .swf
• .html
• .csv
• .xhtm
• .dat

It does the following:

• It avoids encrypting files in folders with the following strings:
  • Windows
  • Microsoft
  • Program
  • All Users
  • Default
  • $Recycle.Bin
• It retrieves the country code by accessing the following URL:
  • http://ip-api.com/json/?fields=countryCode

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

• List of encrypted files
• Windows OS Version
• User's rights (Example: ADMIN)

NOTES:

It displays the following ransom note: