RANSOM_CERBER.DLEZ

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 uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops.

It connects to certain websites to send and receive information. It terminates itself if it detects it is being run in a virtual environment. It deletes the initially executed copy of itself.

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 component file(s):

• {folders containing encrypted files}\# HELPDECRYPT #.html
• {folders containing encrypted files}\# HELPDECRYPT #.txt
• {folders containing encrypted files}\# HELPDECRYPT #.url
• %Desktop%\# HELPDECRYPT #.html
• %Desktop%\# HELPDECRYPT #.txt
• %Desktop%\# HELPDECRYPT #.url
• %Application Data%\{random file names}
• %Application Data%\{filename}.png

(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.. %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 uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops.

Other Details

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

• Uses IP range {BLOCKED}.{BLOCKED}.234.0/23 via port 6892
  
  It sends the following information:
  
  • MD5_KEY
  • PARTNER_ID
  • OS
  • IS_X64
  • IS_ADMIN
  • COUNT_FILES
  • STOP_REASON

It encrypts files with the following extensions:

• .1cd
• .3dm
• .3ds
• .3fr
• .3g2
• .3gp
• .3pr
• .7z
• .7zip
• .aac
• .ab4
• .abd
• .acc
• .accdb
• .accde
• .accdr
• .accdt
• .ach
• .acr
• .act
• .adb
• .adp
• .ads
• .agdl
• .ai
• .aiff
• .ait
• .al
• .aoi
• .apj
• .apk
• .arw
• .ascx
• .asf
• .asm
• .asp
• .aspx
• .asset
• .asx
• .atb
• .avi
• .awg
• .back
• .backup
• .backupdb
• .bak
• .bank
• .bay
• .bdb
• .bgt
• .bik
• .bin
• .bkp
• .blend
• .bmp
• .bpw
• .bsa
• .c
• .cash
• .cdb
• .cdf
• .cdr
• .cdr3
• .cdr4
• .cdr5
• .cdr6
• .cdrw
• .cdx
• .ce1
• .ce2
• .cer
• .cfg
• .cfn
• .cgm
• .cib
• .class
• .cls
• .cmt
• .config
• .contact
• .cpi
• .cpp
• .cr2
• .craw
• .crt
• .crw
• .cry
• .cs
• .csh
• .csl
• .css
• .csv
• .d3dbsp
• .dac
• .das
• .dat
• .db
• .db3
• .db_journal
• .dbf
• .dbx
• .dc2
• .dcr
• .dcs
• .ddd
• .ddoc
• .ddrw
• .dds
• .def
• .der
• .des
• .design
• .dgc
• .dgn
• .dit
• .djvu
• .dng
• .doc
• .docm
• .docx
• .dot
• .dotm
• .dotx
• .drf
• .drw
• .dtd
• .dwg
• .dxb
• .dxf
• .dxg
• .edb
• .eml
• .eps
• .erbsql
• .erf
• .exf
• .fdb
• .ffd
• .fff
• .fh
• .fhd
• .fla
• .flac
• .flb
• .flf
• .flv
• .flvv
• .forge
• .fpx
• .fxg
• .gbr
• .gho
• .gif
• .gray
• .grey
• .groups
• .gry
• .h
• .hbk
• .hdd
• .hpp
• .html
• .ibank
• .ibd
• .ibz
• .idx
• .iif
• .iiq
• .incpas
• .indd
• .info
• .info_
• .ini
• .iwi
• .jar
• .java
• .jnt
• .jpe
• .jpeg
• .jpg
• .js
• .json
• .k2p
• .kc2
• .kdbx
• .kdc
• .key
• .kpdx
• .kwm
• .laccdb
• .lbf
• .lck
• .ldf
• .lit
• .litemod
• .litesql
• .lock
• .log
• .ltx
• .lua
• .m
• .m2ts
• .m3u
• .m4a
• .m4p
• .m4v
• .ma
• .mab
• .mapimail
• .max
• .mbx
• .md
• .mdb
• .mdc
• .mdf
• .mef
• .mfw
• .mid
• .mkv
• .mlb
• .mmw
• .mny
• .money
• .moneywell
• .mos
• .mov
• .mp3
• .mp4
• .mpeg
• .mpg
• .mrw
• .msf
• .msg
• .myd
• .nd
• .ndd
• .ndf
• .nef
• .nk2
• .nop
• .nrw
• .ns2
• .ns3
• .ns4
• .nsd
• .nsf
• .nsg
• .nsh
• .nvram
• .nwb
• .nx2
• .nxl
• .nyf
• .oab
• .obj
• .odb
• .odc
• .odf
• .odg
• .odm
• .odp
• .ods
• .odt
• .ogg
• .oil
• .omg
• .one
• .orf
• .ost
• .otg
• .oth
• .otp
• .ots
• .ott
• .p12
• .p7b
• .p7c
• .pab
• .pages
• .pas
• .pat
• .pbf
• .pcd
• .pct
• .pdb
• .pdd
• .pdf
• .pef
• .pem
• .pfx
• .php
• .pif
• .pl
• .plc
• .plus_muhd
• .pm
• .pm!
• .pmi
• .pmj
• .pml
• .pmm
• .pmo
• .pmr
• .pnc
• .pnd
• .png
• .pnx
• .pot
• .potm
• .potx
• .ppam
• .pps
• .ppsm
• .ppsx
• .ppt
• .pptm
• .pptx
• .prf
• .private
• .ps
• .psafe3
• .psd
• .pspimage
• .pst
• .ptx
• .pub
• .pwm
• .py
• .qba
• .qbb
• .qbm
• .qbr
• .qbw
• .qbx
• .qby
• .qcow
• .qcow2
• .qed
• .qtb
• .r3d
• .raf
• .rar
• .rat
• .raw
• .rdb
• .re4
• .rm
• .rtf
• .rvt
• .rw2
• .rwl
• .rwz
• .s3db
• .safe
• .sas7bdat
• .sav
• .save
• .say
• .sd0
• .sda
• .sdb
• .sdf
• .sh
• .sldm
• .sldx
• .slm
• .sql
• .sqlite
• .sqlite-shm
• .sqlite-wal
• .sqlite3
• .sqlitedb
• .sr2
• .srb
• .srf
• .srs
• .srt
• .srw
• .st4
• .st5
• .st6
• .st7
• .st8
• .stc
• .std
• .sti
• .stl
• .stm
• .stw
• .stx
• .svg
• .swf
• .sxc
• .sxd
• .sxg
• .sxi
• .sxm
• .sxw
• .tax
• .tbb
• .tbk
• .tbn
• .tex
• .tga
• .thm
• .tif
• .tiff
• .tlg
• .tlx
• .txt
• .upk
• .usr
• .vbox
• .vdi
• .vhd
• .vhdx
• .vmdk
• .vmsd
• .vmx
• .vmxf
• .vob
• .vpd
• .vsd
• .wab
• .wad
• .wallet
• .war
• .wav
• .wb2
• .wma
• .wmf
• .wmv
• .wpd
• .wps
• .x11
• .x3f
• .xis
• .xla
• .xlam
• .xlk
• .xlm
• .xlr
• .xls
• .xlsb
• .xlsm
• .xlsx
• .xlt
• .xltm
• .xltx
• .xlw
• .xml
• .xps
• .xxx
• .ycbcra
• .yuv
• .zip

It renames encrypted files using the following names:

• {random name}.cerber3

It terminates itself if it detects it is being run in a virtual environment.

It does the following:

• It terminates itself if found running in any of the following countries:
  • Armenia
  • Azerbaijan
  • Belarus
  • Georgia
  • Kyrgyzstan
  • Kazakhstan
  • Moldova
  • Russia
  • Turkmenistan
  • Tajikistan
  • Ukraine
  • Uzbekistan
• It avoids encrypting the following files:
  • bootsect.bak
  • iconcache.db
  • ntuser.dat
  • thumbs.db
• It skips to encrypt the following paths:
  • :\\$recycle.bin\\
  • :\\$windows.~bt\\
  • :\\boot\\
  • :\\documents and settings\\all users\\
  • :\\documents and settings\\default user\\
  • :\\documents and settings\\localservice\\
  • :\\documents and settings\\networkservice\\
  • :\\program files\\
  • :\\program files (x86)\\
  • :\\programdata\\
  • :\\recovery\\
  • :\\recycler\\
  • :\\users\\all users\\
  • :\\windows\\
  • :\\windows.old\\
  • \\appdata\\local\\
  • \\appdata\\locallow\\
  • \\appdata\\roaming\\adobe\\flash player\\
  • \\appData\\roaming\\apple computer\\safari\\
  • \\appdata\\roaming\\ati\\
  • \\appdata\\roaming\\intel\\
  • \\appdata\\roaming\\intel corporation\\
  • \\appdata\\roaming\\google\\
  • \\appdata\\roaming\\macromedia\\flash player\\
  • \\appdata\\roaming\\mozilla\\
  • \\appdata\\roaming\\nvidia\\
  • \\appdata\\roaming\\opera\\
  • \\appdata\\roaming\\opera software\\
  • \\appdata\\roaming\\microsoft\\internet explorer\\
  • \\appdata\\roaming\\microsoft\\windows\\
  • \\application data\\microsoft\\
  • \\local settings\\
  • \\public\\music\\sample music\\
  • \\public\\pictures\\sample pictures\\
  • \\public\\videos\\sample videos\\
  • \\tor browser\\
• It executes the dropped VBS component which is responsible for speaking the following message:
  • "Attention! Attention! Attention! Your documents, photos, databases and other important files have been encrypted!"
• It deletes all shadow copies by executing the following command:
  • vssadmin.exe delete shadows /all /quiet
    WMIC.exe shadowcopy delete
• It disables Windows Startup Repair by executing the following command:
  • bcdedit.exe /set {default} recoveryenabled no
  • bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
• It is configured to target related files under the following folders:
  • :\\documents and settings\\all users\\documents\\
  • \\appdata\\roaming\\microsoft\\office\\
  • \\excel\\
  • \\microsoft sql server\\
  • \\onenote\\
  • \\outlook\\
  • \\powerpoint\\
  • \\steam\\
  • \\the bat!\\
  • \\thunderbird\\

It deletes the initially executed copy of itself

NOTES:

This ransomware changes the wallpaper with the following image:

It opens the dropped ransom notes after encrypting the files:

It makes sure that no automation is accessing their servers by adding captcha in their payment system: