Ransom.Win64.MEDUSALOCKER.AC

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 executes then deletes itself afterward.

It encrypts files with specific file extensions. It encrypts files found in specific folders. It drops files as ransom note. It avoids encrypting files with the following file extensions.

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 files:

• %Application Data%\KEY.FILE

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

• vssadmin.exe Resize ShadowStorage /for=c: /on=c: /maxsize=401MB
• vssadmin.exe Resize ShadowStorage /for=c: /on=c: /maxsize=unbounded
• vssadmin.exe Resize ShadowStorage /for=d: /on=d: /maxsize=401MB
• vssadmin.exe Resize ShadowStorage /for=d: /on=d: /maxsize=unbounded
• vssadmin.exe Resize ShadowStorage /for=e: /on=e: /maxsize=401MB
• vssadmin.exe Resize ShadowStorage /for=e: /on=e: /maxsize=unbounded
• vssadmin.exe Resize ShadowStorage /for=f: /on=f: /maxsize=401MB
• vssadmin.exe Resize ShadowStorage /for=f: /on=f: /maxsize=unbounded
• vssadmin.exe Resize ShadowStorage /for=g: /on=g: /maxsize=401MB
• vssadmin.exe Resize ShadowStorage /for=g: /on=g: /maxsize=unbounded
• vssadmin.exe Resize ShadowStorage /for=h: /on=h: /maxsize=401MB
• vssadmin.exe Resize ShadowStorage /for=h: /on=h: /maxsize=unbounded
• vssadmin.exe Delete Shadows /All /Quiet
• del /s /f /q c:\*.VHD c:\*.bac c:\*.bak c:\*.wbcat c:\*.bkf c:\Backup*.* c:\backup*.* c:\*.set c:\*.win c:\*.dsk
• del /s /f /q d:\*.VHD d:\*.bac d:\*.bak d:\*.wbcat d:\*.bkf d:\Backup*.* d:\backup*.* d:\*.set d:\*.win d:\*.dsk
• del /s /f /q e:\*.VHD e:\*.bac e:\*.bak e:\*.wbcat e:\*.bkf e:\Backup*.* e:\backup*.* e:\*.set e:\*.win e:\*.dsk
• del /s /f /q f:\*.VHD f:\*.bac f:\*.bak f:\*.wbcat f:\*.bkf f:\Backup*.* f:\backup*.* f:\*.set f:\*.win f:\*.dsk
• del /s /f /q g:\*.VHD g:\*.bac g:\*.bak g:\*.wbcat g:\*.bkf g:\Backup*.* g:\backup*.* g:\*.set g:\*.win g:\*.dsk
• del /s /f /q h:\*.VHD h:\*.bac h:\*.bak h:\*.wbcat h:\*.bkf h:\Backup*.* h:\backup*.* h:\*.set h:\*.win h:\*.dsk
• del %0
• bcdedit.exe /set {default} recoveryenabled No
• bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
• wbadmin DELETE SYSTEMSTATEBACKUP
• wbadmin DELETE SYSTEMSTATEBACKUP -deleteOldest
• wmic.exe SHADOWCOPY /nointeractive
• %System%\cmd.exe /c del {Malware Path}\{Malware Filename}.exe >> NUL

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

It executes then deletes itself afterward.

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

• {8761ABBD-7F85-42EE-B272-A76179687C63}

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
MSFEEditor = "{Malware Path}\{Malware Filename}.exe" e

It starts the following services:

• LanmanWorkstation

Process Termination

This Ransomware terminates the following services if found on the affected system:

• wrapper
• DefWatch
• ccEvtMgr
• ccSetMgr
• SavRoam
• sqlservr
• sqlagent
• sqladhlp
• Culserver
• RTVscan
• sqlbrowser
• SQLADHLP
• QBIDPService
• Intuit.QuickBooks.FCS
• QBCFMonitorService
• sqlwriter
• msmdsrv
• tomcat6
• zhudongfangyu
• vmware-usbarbitator64
• vmware-converter
• dbsrv12
• dbeng8
• MSSQLServerADHelper100
• MSSQLFDLauncher
• MSSQLSERVER
• MSSQLServerOLAPService
• SQLBrowser
• MsDtsServer100
• ReportServer
• SQLWriter
• SQLSERVERAGENT

It terminates the following processes if found running in the affected system's memory:

• EXCEL.EXE
• wxServer.exe
• wxServerView
• sqlservr.exe
• sqlmangr.exe
• RAgui.exe
• supervise.exe
• Culture.exe
• RTVscan.exe
• Defwatch.exe
• sqlbrowser.exe
• winword.exe
• Winword.exe
• onenotem.exe
• QBW32.exe
• QBDBMgr.exe
• qbupdate.exe
• QBCFMonitorService.exe
• axlbridge.exe
• QBIDPService.exe
• httpd.exe
• fdlauncher.exe
• MsDtsSrvr.exe
• sqlwriter.exe
• fdhost.exe
• ssms.exe
• tomcat6.exe
• java.exe
• 360se.exe
• 360doctor.exe
• wdswfsafe.exe
• GDscan.exe
• ZhuDongFangYu.exe

Other Details

This Ransomware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLinkedConnections = 1

It does the following:

• This ransomware can perform privilege escalation
• It encrypts in all existing drives of the affected system
• It encrypts files from network share
• It empties out the Recycle Bin
• It uses Windows Restart Manager to unlock the files it will encrypt

Ransomware Routine

This Ransomware encrypts files with the following extensions:

• .htmlx
• .vxdh
• .7zip
• .aac
• .abd
• .accdb
• .accde
• .accdr
• .accdt
• .ace
• .ach
• .acr
• .act
• .adb
• .adi
• .adp
• .adr
• .ads
• .aes
• .afi
• .agdl
• .aiff
• .aii
• .air
• .ais
• .ait
• .aiv
• .alg
• .allet
• .ams
• .aocla
• .aoi
• .apj
• .apk
• .arc
• .arch00
• .arm
• .art
• .arw
• .arz
• .asc
• .asf
• .asm
• .asp
• .aspx
• .asset
• .asx
• .avhdx
• .avi
• .awg
• .backup
• .backupdb
• .bank
• .bar
• .bat
• .bay
• .bck
• .bco
• .bdb
• .bgt
• .big
• .bik
• .bin
• .bkf
• .bkp
• .bkup
• .blend
• .blob
• .bmp
• .bpn
• .bpw
• .brd
• .bsa
• .bsm
• .bxl
• .cad
• .cam
• .cas
• .cbk
• .cbu
• .cdf
• .cdr
• .cdr3
• .cdr4
• .cdr5
• .cdr6
• .cdrw
• .cdx
• .cel
• .cer
• .cert
• .cfg
• .cfr
• .cgi
• .cgm
• .chg
• .cib
• .ckt
• .class
• .classpath
• .cls
• .cmd
• .cmt
• .cnf
• .con
• .config
• .contact
• .cpa
• .cpi
• .cpp
• .cpr
• .craw
• .crt
• .crw
• .csa
• .csh
• .cshtml
• .csl
• .csr
• .css
• .csv
• .ctl
• .cwz
• .d3dbsp
• .dac
• .das
• .data
• .dazip
• .db_journal
• .dba
• .dbc
• .dbf
• .dbs
• .dbx
• .dch
• .dcr
• .dcs
• .ddb
• .ddd
• .ddoc
• .ddrw
• .dds
• .der
• .des
• .desc
• .design
• .dft
• .dgc
• .dif
• .dip
• .dit
• .djvu
• .dmp
• .dng
• .doc
• .docb
• .docm
• .docx
• .dot
• .dotm
• .dotx
• .dra
• .drf
• .drl
• .dru
• .drw
• .dsn
• .dsnwrk
• .dtd
• .dwg
• .dxb
• .dxf
• .dxg
• .ecf
• .edb
• .edf
• .elt
• .eml
• .emz
• .epk
• .eps
• .erbsql
• .erf
• .esm
• .ewprj
• .exf
• .fdb
• .ffd
• .fff
• .fhd
• .fla
• .flac
• .flf
• .flp
• .flv
• .flvv
• .fods
• .fodt
• .forge
• .fos
• .fpd
• .fpk
• .fpx
• .frm
• .fsh
• .fxg
• .gbk
• .gbl
• .gbo
• .gbp
• .gbr
• .gbs
• .gbx
• .gdb
• .gho
• .gif
• .gko
• .gml
• .gpb
• .gpg
• .gpt
• .gray
• .grb
• .grey
• .groups
• .gry
• .gtl
• .gto
• .gtp
• .gts
• .gwk
• .hbk
• .hdd
• .hkdb
• .hkx
• .hplg
• .hpp
• .html
• .hvpl
• .hwp
• .ibank
• .ibd
• .ibz
• .icxs
• .idb
• .idc
• .iif
• .iiq
• .incpas
• .indd
• .info
• .ink
• .ipc
• .ism
• .iso
• .itdb
• .itl
• .itm
• .iwd
• .iwi
• .jar
• .java
• .jnt
• .jpe
• .jpeg
• .jpg
• .jrl
• .jsp
• .kdb
• .kdbx
• .kdc
• .kicad
• .kpdx
• .kwm
• .laccdb
• .lay
• .lay6
• .layout
• .lbf
• .lbr
• .lck
• .ldb
• .ldf
• .lgc
• .lia
• .lib
• .libprj
• .license
• .licz
• .lit
• .litemod
• .llx
• .lmc
• .log
• .lrf
• .ltx
• .lua
• .lvl
• .lyt
• .lzh
• .lzma
• .m2ts
• .map
• .mapimail
• .max
• .mbx
• .mcmeta
• .mdb
• .mdbackup
• .mdc
• .mddata
• .mdf
• .mef
• .menu
• .mfw
• .mid
• .mkv
• .mlb
• .mlx
• .mml
• .mmw
• .mny
• .moneywell
• .mos
• .mov
• .mpeg
• .mpg
• .mpqge
• .mrg
• .mrw
• .mrwref
• .msg
• .mst
• .mts
• .myd
• .myi
• .mysql
• .mysqli
• .nbd
• .ncf
• .ndd
• .ndf
• .nef
• .nop
• .nrw
• .nsd
• .nsf
• .nsg
• .nsh
• .ntl
• .nvram
• .nwb
• .nxl
• .nyf
• .oab
• .obj
• .obk
• .odb
• .odc
• .odf
• .odg
• .odm
• .odp
• .ods
• .odt
• .oeb
• .ogg
• .oil
• .olb
• .one
• .onetoc2
• .opj
• .opt
• .ora
• .orf
• .ost
• .otg
• .oth
• .otp
• .ots
• .ott
• .pab
• .pad
• .pages
• .pak
• .paq
• .par
• .pas
• .pat
• .pbd
• .pcb
• .pcbdoc
• .pcd
• .pct
• .pdb
• .pdblib
• .pdd
• .pdf
• .pef
• .pem
• .pfx
• .phj
• .phl
• .pho
• .php
• .pif
• .pkpass
• .plc
• .plus_muhd
• .png
• .pot
• .potm
• .potx
• .ppam
• .ppc
• .pps
• .ppsm
• .ppsx
• .ppt
• .pptm
• .pptx
• .prf
• .prj
• .prjcor
• .prjemb
• .prjpcb
• .pro
• .project
• .prt
• .psafe3
• .psc
• .psd
• .psk
• .psm
• .pspimage
• .pst
• .ptx
• .pwm
• .qba
• .qbb
• .qbk
• .qbm
• .qbmb
• .qbmd
• .qbquery
• .qbr
• .qbw
• .qbx
• .qby
• .qcow
• .qcow2
• .qdf
• .qed
• .qfd
• .qfx
• .qic
• .qif
• .qmd
• .qry
• .quicken
• .quicken2015backup
• .quicken2016backup
• .quicken2017backup
• .raf
• .rar
• .rat
• .raw
• .rdb
• .reu
• .rgss3a
• .rim
• .rofl
• .rou
• .rtf
• .rul
• .rvt
• .rwl
• .rwz
• .s3db
• .safe
• .sal
• .sas7bdat
• .sav
• .save
• .say
• .sbn
• .sbx
• .sch
• .schdoc
• .schlib
• .sda
• .sdf
• .shp
• .shx
• .sid
• .sidd
• .sidn
• .sie
• .sis
• .sldm
• .sldx
• .slk
• .slm
• .sln
• .snt
• .snx
• .spp
• .sqb
• .sql
• .sqlite
• .sqlite3
• .sqlitedb
• .sqr
• .srf
• .srt
• .srw
• .ssq
• .stc
• .std
• .sti
• .stm
• .stp
• .stw
• .stx
• .sum
• .suo
• .svg
• .swf
• .sxc
• .sxd
• .sxg
• .sxi
• .sxm
• .sxw
• .syncdb
• .tar
• .tax
• .tbk
• .tcf
• .tex
• .tga
• .tgz
• .thm
• .tib
• .tif
• .tiff
• .tlg
• .tmd
• .tmp
• .tor
• .trn
• .txt
• .uop
• .uot
• .upk
• .vbk
• .vbm
• .vbox
• .vbs
• .vcd
• .vcf
• .vdf
• .vdi
• .vfs0
• .vhd
• .vhdx
• .vib
• .vlb
• .vmdk
• .vmem
• .vmsd
• .vmx
• .vmxf
• .vob
• .vom
• .vpk
• .vpp_pc
• .vsd
• .vsdx
• .vtf
• .wab
• .wad
• .wallet
• .wav
• .wbk
• .wdb
• .wks
• .wma
• .wmo
• .wmv
• .wotreplay
• .wpd
• .wps
• .xgo
• .xis
• .xla
• .xlam
• .xlc
• .xlk
• .xlm
• .xlr
• .xls
• .xlsb
• .xlsm
• .xlsx
• .xlt
• .xltm
• .xltx
• .xlw
• .xml
• .xps
• .xslt
• .xxx
• .ycbcra
• .ydk
• .zip
• .zpd
• .ztmp

It encrypts files found in the following folders:

• \Program Files\Microsoft\Exchange Server
• \Program Files (x86)\Microsoft\Exchange Server
• \Program Files\Microsoft SQL Server
• \Program Files (x86)\Microsoft SQL Server

It avoids encrypting files found in the following folders:

• %All Users Profile%
• %User Profile%\AppData
• %Windows%
• %Program Files%
• %System Root%
• %Application Data%
• \intel
• \nvidia

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). . %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It appends the following extension to the file name of the encrypted files:

• {Original Filename}.{Original Extension}.ReadInstructions

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

• %Desktop%\Recovery_Instructions.mht
• {Drive Letter}\Recovery_Instructions.mht
  

It avoids encrypting files with the following file extensions:

• .dat
• .dll
• .exe
• .mht
• .ini
• .sys
• .lnk
• .sys
• .Readinstructions