RANSOM_LOCKY.DLDTASL
Trojan-Ransom.Win32.Locky.xlz(Kaspersky);Troj/Locky-ZI(Sophos);W32/Locky.FOGX!tr(Fortinet)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 deletes itself after execution.
TECHNICAL DETAILS
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 files:
- (Folder of Encrypted Files}\OSIRIS-{Random Hex Values}.htm → Ransom Note
It drops and executes the following files:
- %User Profile%\DesktopOSIRIS.bmp → Ransom Note, image used as wallpaper
- %User Profile%\DesktopOSIRIS.htm → Ransom Note
(Note: %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.)
Other System Modifications
This Trojan modifies the following file(s):
- It encrypts files in fixed, removable, RAM disk drives, and network shares.
It adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = 0
(Note: The default value data of the said registry entry is {user preference}.)
HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = 0
(Note: The default value data of the said registry entry is {user preference}.)
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Profile%\DesktopOSIRIS.bmp
(Note: The default value data of the said registry entry is {user preference}.)
It sets the system's desktop wallpaper to the following image:
Other Details
This Trojan connects to the following website to send and receive information:
- http://{BLOCKED}.{BLOCKED}.217.65/checkupdate
- http://{BLOCKED}.{BLOCKED}.28.162/checkupdate
It encrypts files with the following extensions:
- .001
- .002
- .003
- .004
- .005
- .006
- .007
- .008
- .009
- .010
- .011
- .123
- .1cd
- .3dm
- .3ds
- .3fr
- .3g2
- .3gp
- .3pr
- .602
- .7z
- .7zip
- .aac
- .ab4
- .accdb
- .accde
- .accdr
- .accdt
- .ach
- .acr
- .act
- .adb
- .adp
- .ads
- .aes
- .agdl
- .ai
- .aiff
- .ait
- .al
- .aoi
- .apj
- .apk
- .ARC
- .arw
- .asc
- .asf
- .asm
- .asp
- .aspx
- .asset
- .asx
- .avi
- .awg
- .back
- .backup
- .backupdb
- .bak
- .bank
- .bat
- .bay
- .bdb
- .bgt
- .bik
- .bin
- .bkp
- .blend
- .bmp
- .bpw
- .brd
- .bsa
- .bz2
- .c
- .cdf
- .cdr
- .cdr3
- .cdr4
- .cdr5
- .cdr6
- .cdrw
- .cdx
- .ce1
- .ce2
- .cer
- .cfg
- .cgm
- .cib
- .class
- .cls
- .cmd
- .cmt
- .config
- .contact
- .cpi
- .cpp
- .cr2
- .craw
- .crt
- .crw
- .cs
- .csh
- .csl
- .csr
- .css
- .csv
- .CSV
- .d3dbsp
- .dac
- .das
- .dat
- .db
- .db_journal
- .db3
- .dbf
- .dbx
- .dc2
- .dch
- .dcr
- .dcs
- .ddd
- .ddoc
- .ddrw
- .dds
- .der
- .des
- .design
- .dgc
- .dif
- .dip
- .dit
- .djv
- .djvu
- .dng
- .doc
- .DOC
- .docb
- .docm
- .docx
- .dot
- .DOT
- .dotm
- .dotx
- .drf
- .drw
- .dtd
- .dwg
- .dxb
- .dxf
- .dxg
- .edb
- .eml
- .eps
- .erbsql
- .erf
- .exf
- .fdb
- .ffd
- .fff
- .fh
- .fhd
- .fla
- .flac
- .flf
- .flv
- .flvv
- .forge
- .fpx
- .frm
- .fxg
- .gif
- .gpg
- .gray
- .grey
- .groups
- .gry
- .gz
- .h
- .hbk
- .hdd
- .hpp
- .html
- .hwp
- .ibank
- .ibd
- .ibz
- .idx
- .iif
- .iiq
- .incpas
- .indd
- .iwi
- .jar
- .java
- .jnt
- .jpe
- .jpeg
- .jpg
- .js
- .kc2
- .kdbx
- .kdc
- .key
- .kpdx
- .kwm
- .laccdb
- .lay
- .lay6
- .lbf
- .ldf
- .lit
- .litemod
- .litesql
- .log
- .ltx
- .lua
- .m
- .m2ts
- .m3u
- .m4a
- .m4p
- .m4u
- .m4v
- .mapimail
- .max
- .mbx
- .md
- .mdb
- .mdc
- .mdf
- .mef
- .mfw
- .mid
- .mkv
- .mlb
- .mml
- .mmw
- .mny
- .moneywell
- .mos
- .mov
- .mp3
- .mp4
- .mpeg
- .mpg
- .mrw
- .ms11
- .ms11 (Security copy)
- .msg
- .myd
- .MYD
- .MYI
- .n64
- .nd
- .ndd
- .ndf
- .nef
- .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
- .onetoc2
- .orf
- .ost
- .otg
- .oth
- .otp
- .ots
- .ott
- .p12
- .p7b
- .p7c
- .pab
- .pages
- .PAQ
- .pas
- .pat
- .pcd
- .pct
- .pdb
- .pdd
- .pef
- .pem
- .pfx
- .php
- .pif
- .pl
- .plc
- .plus_muhd
- .png
- .pot
- .potm
- .potx
- .ppam
- .pps
- .ppsm
- .ppsx
- .ppt
- .PPT
- .pptm
- .pptx
- .prf
- .ps
- .psafe3
- .psd
- .pspimage
- .pst
- .ptx
- .pwm
- .py
- .qba
- .qbb
- .qbm
- .qbr
- .qbw
- .qbx
- .qby
- .qcow
- .qcow2
- .qed
- .r3d
- .raf
- .rar
- .rat
- .raw
- .rb
- .rdb
- .re4
- .rm
- .RTF
- .rtf
- .rvt
- .rw2
- .rwl
- .rwz
- .s3db
- .safe
- .sas7bdat
- .sav
- .save
- .say
- .sch
- .sd0
- .sda
- .sdf
- .sh
- .sldm
- .sldx
- .slk
- .sql
- .sqlite
- .sqlite3
- .SQLITE3
- .sqlitedb
- .SQLITEDB
- .sr2
- .srf
- .srt
- .srw
- .st4
- .st5
- .st6
- .st7
- .st8
- .stc
- .std
- .sti
- .stm
- .stw
- .stx
- .svg
- .swf
- .sxc
- .sxd
- .sxg
- .sxi
- .sxm
- .sxw
- .tar
- .tar
- .tbk
- .tex
- .tga
- .tgz
- .thm
- .tif
- .tiff
- .tlg
- .txt
- .uop
- .uot
- .upk
- .vb
- .vbox
- .vbs
- .vdi
- .vhd
- .vhdx
- .vmdk
- .vmsd
- .vmx
- .vmxf
- .vob
- .wab
- .wad
- .wallet
- .wav
- .wb2
- .wk1
- .wks
- .wma
- .wmv
- .wpd
- .wps
- .x11
- .x3f
- .xis
- .xla
- .xlam
- .xlc
- .xlk
- .xlm
- .xlr
- .xls
- .XLS
- .xlsb
- .xlsm
- .xlsx
- .xlt
- .xltm
- .xltx
- .xlw
- .xml
- .ycbcra
- .yuv
- .zip
- wallet.dat
It renames encrypted files using the following names:
- {first 8 characters of ID}--{next 4 characters of ID}--{last 4 characters of ID}--{8 hex characters}--{12 hex characters}.osiris
It does the following:
- It prevents encrypting files containing any of the strings in its full path name:
- $Recycle.Bin
- _HELP_instructions.bmp
- _HELP_instructions.html
- _HELP_instructions.txt
- _Locky_recover_instructions.bmp
- _Locky_recover_instructions.txt
- AppData
- Application Data
- Boot
- Program Files
- Program Files (x86)
- System Volume Information
- temp
- thumbs.db
- tmp
- Windows
- winnt
- It deletes shadow copies by executing the following command:
- vssadmin.exe Delete Shadows /Quiet /All
It drops the following ransom note:
It deletes itself after execution.
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Search and delete this file
- (Folder of Encrypted Files}\OSIRIS-{Random Hex Values}.htm
- %User Profile%\DesktopOSIRIS.bmp
- %User Profile%\DesktopOSIRIS.htm
Step 4
Reset your Desktop properties
Step 5
Scan your computer with your Trend Micro product to delete files detected as RANSOM_LOCKY.DLDTASL. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 6
Restore encrypted files from backup.
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