RANSOM_VENUSLOCK.C

January 04, 2017
 Analysis by: Michael Jay Villanueva
 ALIASES:

Ransom:MSIL/VenusLocker.A (Microsoft)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

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.

  TECHNICAL DETAILS

File Size:

608,098 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

02 Jan 2017

Payload:

Connects to URLs/IPs, Displays graphics/image, Encrypts files

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.

Autostart Technique

This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\x.vbs -> executes the malware

(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.)

Dropping Routine

This Trojan drops the following files:

  • %Desktop%\ReadMe.txt -> Ransom Note
  • %User Profile%\UFsdGVkX1DKeRC.vluni -> used by the malware as an indicator that the system is already infected

(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.. %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.)

Download Routine

This Trojan accesses the following websites to download files:

  • http://i.{BLOCKED}r.com/rSFPH6m.jpg

It saves the files it downloads using the following names:

  • %User Profile%\bg.jpg -> Used as wallpaper

(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.)

Information Theft

This Trojan gathers the following data:

  • Username
  • Computer Name
  • Language
  • OS Version
  • Time
  • User ID

Other Details

This Trojan connects to the following URL(s) to get the affected system's IP address:

  • http://{BLOCKED}i.com/csv?fields=country

It connects to the following website to send and receive information:

  • http://ransom.{BLOCKED}aioskdo.info/create.php
  • http://ransom.{BLOCKED}aioskdo.info/keysave.php

It encrypts files with the following extensions:

  • Full Encryption:
    • .txt
    • .ini
    • .php
    • .html
    • .css
    • .py
    • .c
    • .cpp
    • .cc
    • .h
    • .cs
    • .log
    • .pl
    • .java
    • .doc
    • .dot
    • .docx
    • .docm
    • .dotx
    • .dotm
    • .rtf
    • .wpd
    • .docb
    • .wps
    • .msg
    • .xls
    • .xlt
    • .xlm
    • .xlsx
    • .xlsm
    • .xltx
    • .xltm
    • .xlsb
    • .xla
    • .xlam
    • .xll
    • .xlw
    • .ppt
    • .pot
    • .pps
    • .pptx
    • .pptm
    • .potx
    • .potm
    • .ppam
    • .ppsx
    • .ppsm
    • .sldx
    • .sldm
    • .class
    • .jar
    • .csv
    • .xml
    • .dwg
    • .dxf
    • .asp
  • Encrypts only the first 1024 bytes of file with the following extensions:
    • .asf
    • .pdf
    • .mp3
    • .waw
    • .jpg
    • .jpeg
    • .rar
    • .zip
    • .psd
    • .tif
    • .wma
    • .gif
    • .bmp
    • .ppd
    • .eps
    • .png
    • .ace
    • .djvu
    • .tar
    • .cdr
    • .max
    • .wmv
    • .avi
    • .wav
    • .mp4
    • .pdd
    • .aac
    • .ac3
    • .amf
    • .amr
    • .accdb
    • .mod
    • .tax2013
    • .tax2014
    • .oga
    • .ogg
    • .pbf
    • .ra
    • .raw
    • .saf
    • .val
    • .wave
    • .wow
    • .wpk
    • .3g2
    • .3gp
    • .3gp2
    • .3mm
    • .amx
    • .avs
    • .bik
    • .dir
    • .divx
    • .dvx
    • .evo
    • .flv
    • .qtq
    • .tch
    • .rts
    • .rum
    • .rv
    • .scn
    • .srt
    • .stx
    • .svi
    • .swf
    • .trp
    • .vdo
    • .wm
    • .wmd
    • .wmmp
    • .wmx
    • .wvx
    • .xvid
    • .3d
    • .3d4
    • .3df8
    • .pbs
    • .adi
    • .ais
    • .amu
    • .arr
    • .bmc
    • .bmf
    • .cag
    • .cam
    • .dng
    • .ink
    • .jif
    • .jiff
    • .jpc
    • .jpf
    • .jpw
    • .mag
    • .mic
    • .mip
    • .msp
    • .nav
    • .ncd
    • .odc
    • .odi
    • .opf
    • .qif
    • .xwd
    • .abw
    • .act
    • .adt
    • .aim
    • .ans
    • .asc
    • .ase
    • .bdp
    • .bdr
    • .bib
    • .boc
    • .crd
    • .diz
    • .dvi
    • .dxe
    • .mlx
    • .err
    • .euc
    • .faq
    • .fdr
    • .fds
    • .gthr
    • .idx
    • .kwd
    • .lp2
    • .ltr
    • .man
    • .mbox
    • .nfo
    • .now
    • .odm
    • .oft
    • .pwi
    • .rng
    • .rtx
    • .run
    • .ssa
    • .text
    • .unx
    • .wbk
    • .wsh
    • .7z
    • .arc
    • .ari
    • .arj
    • .car
    • .cbr
    • .cbz
    • .gz
    • .gzig
    • .jgz
    • .pak
    • .pcv
    • .puz
    • .rev
    • .sdn
    • .sen
    • .sfs
    • .sfx
    • .sh
    • .shar
    • .shr
    • .sqx
    • .tbz2
    • .tg
    • .tlz
    • .vsi
    • .wad
    • .war
    • .xpi
    • .z02
    • .z04
    • .zap
    • .zipx
    • .zoo
    • .ipa
    • .isu
    • .js
    • .udf
    • .adr
    • .ap
    • .aro
    • .asa
    • .ascx
    • .ashx
    • .asmx
    • .indd
    • .asr
    • .qbb
    • .bml
    • .cer
    • .cms
    • .crt
    • .dap
    • .htm
    • .moz
    • .svr
    • .url
    • .wdgt
    • .abk
    • .bic
    • .big
    • .blp
    • .bsp
    • .cgf
    • .chk
    • .col
    • .cty
    • .dem
    • .elf
    • .ff
    • .gam
    • .grf
    • .h3m
    • .h4r
    • .iwd
    • .ldb
    • .lgp
    • .lvl
    • .map
    • .md3
    • .mdl
    • .nds
    • .pbp
    • .ppf
    • .pwf
    • .pxp
    • .sad
    • .sav
    • .scm
    • .scx
    • .sdt
    • .spr
    • .sud
    • .uax
    • .umx
    • .unr
    • .uop
    • .usa
    • .usx
    • .ut2
    • .ut3
    • .utc
    • .utx
    • .uvx
    • .uxx
    • .vmf
    • .vtf
    • .w3g
    • .w3x
    • .wtd
    • .wtf
    • .ccd
    • .cd
    • .cso
    • .disk
    • .dmg
    • .dvd
    • .fcd
    • .flp
    • .img
    • .isz
    • .mdf
    • .mds
    • .nrg
    • .nri
    • .vcd
    • .vhd
    • .snp
    • .bkf
    • .ade
    • .adpb
    • .dic
    • .cch
    • .ctt
    • .dal
    • .ddc
    • .ddcx
    • .dex
    • .dif
    • .dii
    • .itdb
    • .itl
    • .kmz
    • .lcd
    • .lcf
    • .mbx
    • .mdn
    • .odf
    • .odp
    • .ods
    • .pab
    • .pkb
    • .pkh
    • .psa
    • .qdf
    • .qel
    • .rgn
    • .rrt
    • .rsw
    • .rte
    • .sdb
    • .sdc
    • .sds
    • .sql
    • .stt
    • .tcx
    • .thmx
    • .txd
    • .txf
    • .upoi
    • .vmt
    • .wks
    • .wmdb
    • .xl
    • .xlc
    • .xlr
    • .xlsb
    • .ltm
    • .xlwx
    • .mcd
    • .cap
    • .cod
    • .cp
    • .csi
    • .dcp
    • .dcu
    • .dev
    • .dob
    • .dox
    • .dpk
    • .dpl
    • .dpr
    • .dsk
    • .dsp
    • .eql
    • .ex
    • .f90
    • .fla
    • .for
    • .fpp
    • .jav
    • .lbi
    • .owl
    • .plc
    • .pli
    • .pm
    • .res
    • .rsrc
    • .so
    • .swd
    • .tpu
    • .tpx
    • .tu
    • .tur
    • .vc
    • .yab
    • .aip
    • .amxx
    • .ape
    • .api
    • .mxp
    • .oxt
    • .qpx
    • .qtr
    • .xlv
    • .xpt
    • .cfg
    • .cwf
    • .dbb
    • .slt
    • .bp2
    • .bp3
    • .bpl
    • .clr
    • .dbx
    • .jc
    • .prc
    • .prt
    • .shw
    • .std
    • .ver
    • .wpl
    • .yps
    • .1cd
    • .bck
    • .bak
    • .odt
    • .pst
    • .mpg
    • .mpeg
    • .odb
    • .xlk
    • .mdb
    • .dxg
    • .wb2
    • .dbf
    • .ai
    • .3fr
    • .arw
    • .srf
    • .sr2
    • .bay
    • .crw
    • .cr2
    • .dcr
    • .kdc
    • .erf
    • .mef
    • .mrw
    • .nef
    • .nrw
    • .orf
    • .raf
    • .rwl
    • .rw2
    • .r3d
    • .ptx
    • .pef
    • .srw
    • .x3f
    • .der
    • .pem
    • .pfx
    • .p12
    • .p7b
    • .p7c
    • .jfif
    • .exif
    • .db
    • .pdb
    • .dat
    • .spv
    • .grle
    • .sv5
    • .game
    • .slot
    • .aaf
    • .aep
    • .aepx
    • .plb
    • .prel
    • .prproj
    • .eat
    • .ppj
    • .indl
    • .indt
    • .indb
    • .inx
    • .idml
    • .pmd
    • .xqx
    • .svg
    • .as3
    • .as

It renames encrypted files using the following names:

  • Fully-encrypted files:
    • {Base64-encoded filename and extension}.Venusf
  • Files that were not fully-encrypted (first 1024 bytes only):
    • {Base64-encoded filename and extension}.Venusp

It does the following:

  • It checks for the machine environment and for the following string for its Anti-VM routine:
    • vmware
    • VirtualBox
    • VIRTUAL
  • It prevents encrypting files containing any of the strings in its full path name:
    • Program Files
    • Program Files (x86)
    • Windows
    • Python27
    • Python34
    • AliWangWang
    • Avira
    • wamp
    • 360
    • ATI
    • Google
    • Intel
    • Internet Explorer
    • Kaspersky Lab
    • Microsoft Bing Pinyin
    • Microsoft Chart Controls
    • Microsoft Games
    • Microsoft Office
    • Microsoft.NET
    • MicrosoftBAF
    • MSBuild
    • QQMailPlugin
    • Realtek
    • Skype
    • Reference Assemblies
    • Tencent
    • USB Camera2
    • WinRAR
    • Windows Sidebar
    • Windows Portable Devices
    • Windows Photo Viewer
    • Windows NT
    • Windows Media Player
    • Windows Mail
    • NVIDIA Corporation
    • Adobe
    • IObit
    • AVAST Software
    • CCleaner
    • AVG
    • Mozilla Firefox
    • VirtualDJ
    • TeamViewer
    • ICQ
    • java
    • Yahoo!

NOTES:

This ransomware drops the following ransom note:

This lockscreen is displayed by the ransomware in order to restrict the user from doing any activities on the machine/system:

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

13.132.07

FIRST VSAPI PATTERN DATE:

02 Jan 2017

VSAPI OPR PATTERN File:

13.133.00

VSAPI OPR PATTERN Date:

03 Jan 2017

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

Restart in Safe Mode

[ Learn More ]

Step 4

Reset your Desktop properties

[ Learn More ]

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Startup%\x.vbs
  • %Desktop%\ReadMe.txt
  • %User Profile%\UFsdGVkX1DKeRC.vluni
  • %User Profile%\bg.jpg

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_VENUSLOCK.C. 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 7

Restore encrypted files from backup.


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