Analysis by: Michael Jhon Ofiaza
ALIASES:

Trojan-Ransom.Win32.Gen.hql (Kaspersky) ; Mal/Infitear-A (Sophos-Lite) ; Ransom:Win32/Genasom (Microsoft)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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 encrypts files with specific file extensions. It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 27,648 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 26 Mar 2018
Payload: Drops files, Encrypts files, Displays message/message boxes

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:

  • %System Root%\Perfect.sys -> Use to check if the machine is already infected

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

Other Details

This Ransomware does the following:

  • It deletes shadow copies by executing the following command:
    • cmd.exe /C vssadmin.exe delete shadows /all /Quiet
    • cmd.exe /C WMIC.exe shadowcopy delete
    • cmd.exe /C Bcdedit.exe /set {default} recoveryenabled no
    • cmd.exe /C Bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
    • cmd.exe /C wevtutil.exe cl Application
    • cmd.exe /C wevtutil.exe cl Security
    • cmd.exe /C wevtutil.exe cl System

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .gif
  • .apk
  • .groups
  • .hdd
  • .hpp
  • .log
  • .m2ts
  • .m4p
  • .mkv
  • .mpeg
  • .epub
  • .yuv
  • .ndf
  • .nvram
  • .ogg
  • .ost
  • .pab
  • .pdb
  • .pif
  • .png
  • .qed
  • .qcow
  • .otp
  • .s3db
  • .qcow2
  • .rvt
  • .st7
  • .stm
  • .vbox
  • .vdi
  • .vhd
  • .vhdx
  • .vmdk
  • .vmsd
  • .psafe3
  • .vmx
  • .vmxf
  • .3fr
  • .3pr
  • .ab4
  • .accde
  • .accdr
  • .accdt
  • .ach
  • .acr
  • .sd0
  • .sxw
  • .adb
  • .advertisements
  • .agdl
  • .ait
  • .apj
  • .asm
  • .awg
  • .back
  • .backup
  • .sti
  • .oil
  • .backupdb
  • .bay
  • .bdb
  • .bgt
  • .bik
  • .bpw
  • .cdr3
  • .cdr4
  • .cdr5
  • .cdr6
  • .ycbcra
  • .cdrw
  • .ce1
  • .ce2
  • .cib
  • .craw
  • .crw
  • .csh
  • .csl
  • .db_journal
  • .dc2
  • .pptm
  • .dcs
  • .ddoc
  • .ddrw
  • .der
  • .des
  • .dgc
  • .djvu
  • .dng
  • .drf
  • .dxg
  • .eml
  • .ppt
  • .erbsql
  • .erf
  • .exf
  • .ffd
  • .fh
  • .fhd
  • .gray
  • .grey
  • .gry
  • .hbk
  • .ibd
  • .7z
  • .ibz
  • .iiq
  • .incpas
  • .jpe
  • .kc2
  • .kdbx
  • .kdc
  • .kpdx
  • .lua
  • .mdc
  • .mef
  • .config
  • .mfw
  • .mmw
  • .mny
  • .mrw
  • .myd
  • .ndd
  • .nef
  • .nk2
  • .nop
  • .nrw
  • .ns2
  • .ns3
  • .ldf
  • .ns4
  • .nwb
  • .nx2
  • .nxl
  • .nyf
  • .odb
  • .odf
  • .odg
  • .odm
  • .orf
  • .otg
  • .oth
  • .py
  • .ots
  • .ott
  • .p12
  • .p7b
  • .p7c
  • .pdd
  • .pem
  • .plus_muhd
  • .plc
  • .pot
  • .pptx
  • .py
  • .qba
  • .qbr
  • .qbw
  • .qbx
  • .qby
  • .raf
  • .rat
  • .raw
  • .rdb
  • .rwl
  • .rwz
  • .conf
  • .sda
  • .sdf
  • .sqlite
  • .sqlite3
  • .sqlitedb
  • .sr2
  • .srf
  • .srw
  • .st5
  • .st8
  • .std
  • .stx
  • .sxd
  • .sxg
  • .sxi
  • .sxm
  • .tex
  • .wallet
  • .wb2
  • .wpd
  • .x11
  • .x3f
  • .xis
  • .ARC
  • .contact
  • .dbx
  • .doc
  • .docx
  • .jnt
  • .jpg
  • .msg
  • .oab
  • .ods
  • .pdf
  • .pps
  • .ppsm
  • .prf
  • .pst
  • .rar
  • .rtf
  • .txt
  • .wab
  • .xls
  • .xlsx
  • .xml
  • .zip
  • .1cd
  • .3ds
  • .3g2
  • .7zip
  • .accdb
  • .aoi
  • .asf
  • .asp
  • .aspx
  • .asx
  • .avi
  • .bak
  • .cer
  • .cfg
  • .class
  • .cs
  • .css
  • .csv
  • .db
  • .dds
  • .dwg
  • .dxf
  • .flf
  • .flv
  • .html
  • .idx
  • .js
  • .key
  • .kwm
  • .laccdb
  • .lit
  • .m3u
  • .mbx
  • .md
  • .mdf
  • .mid
  • .mlb
  • .mov
  • .mp3
  • .mp4
  • .mpg
  • .obj
  • .odt
  • .pages
  • .php
  • .psd
  • .pwm
  • .rm
  • .safe
  • .sav
  • .save
  • .sql
  • .srt
  • .swf
  • .thm
  • .vob
  • .wav
  • .wma
  • .wmv
  • .xlsb
  • 3dm
  • .aac
  • .ai
  • .arw
  • .c
  • .cdr
  • .cls
  • .cpi
  • .cpp
  • .cs
  • .db3
  • .docm
  • .dot
  • .dotm
  • .dotx
  • .drw
  • .dxb
  • .eps
  • .fla
  • .flac
  • .fxg
  • .java
  • .m
  • .m4v
  • .max
  • .mdb
  • .pcd
  • .pct
  • .pl
  • .potm
  • .potx
  • .ppam
  • .ppsm
  • .ppsx
  • .pptm
  • .ps
  • .r3d
  • .rw2
  • .sldm
  • .sldx
  • .svg
  • .tga
  • .wps
  • .xla
  • .xlam
  • .xlm
  • .xlr
  • .xlsm
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .act
  • .adp
  • .al
  • .1
  • .bkp
  • .blend
  • .cdf
  • .cdx
  • .cgm
  • .cr2
  • .crt
  • .dac
  • .dbf
  • .dcr
  • .ddd
  • .design
  • .dtd
  • .fdb
  • .fff
  • .fpx
  • .h
  • .iif
  • .indd
  • .jpeg
  • .mos
  • .nd
  • .nsd
  • .nsf
  • .nsg
  • .nsh
  • .odc
  • .odp
  • .pas
  • .pat
  • .pef
  • .pfx
  • .ptx
  • .qbb
  • .qbm
  • .sas7bdat
  • .say
  • .st4
  • .st6
  • .stc
  • .sxc
  • .tlg
  • .wad
  • .xlk
  • .aiff
  • .bmp
  • .cmt
  • .dat
  • .dit
  • .edb
  • .flvv
  • .avhd
  • .back
  • .c
  • .ctl
  • .dbf
  • .disk
  • .dwg
  • .gz
  • .mail
  • .nrg
  • .ora
  • .ova
  • .ovf
  • .pmf
  • .ppt
  • .pptx
  • .pst
  • .pvi
  • .pyc
  • .sln
  • .tar
  • .vbs
  • .vcb
  • .vfd
  • .vmc
  • .vsd
  • .vsdx
  • .vsv
  • .work
  • .xvd
  • .123
  • .3dm
  • .602
  • .aes
  • .asc
  • .brd
  • .bz2
  • .cmd
  • .dch
  • .dif
  • .dip
  • .docb
  • .frm
  • .gpg
  • .jsp
  • .lay
  • .lay6
  • .m4u
  • .mml
  • .myi
  • onetoc2
  • .PAQ
  • .ps1
  • .sch
  • .slk
  • .snt
  • .suo
  • .tgz
  • .tif
  • .tiff
  • .uop
  • .uot
  • .vcd
  • .wk1
  • .wks
  • .xlc

It avoids encrypting files found in the following folders:

  • Windows
  • Program Files
  • $Recycle.Bin
  • Microsoft

It renames encrypted files using the following names:

  • {Random 16 Hex}_ENCRYPTED_BY.WHITEROSE

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

  • {Encrypted Folders}\HOW-TO-RECOVERY-FILES.TXT

NOTES:

This ransomware drops the following as ransom note:

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.166.03
FIRST VSAPI PATTERN DATE: 02 Apr 2018
VSAPI OPR PATTERN File: 14.167.00
VSAPI OPR PATTERN Date: 03 Apr 2018

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

Identify and terminate files detected as RANSOM_WHITEROSE.THDOBAH

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

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.
  • %System Root%\Perfect.sys
  • {Encrypted Folders}\HOW-TO-RECOVERY-FILES.TXT

Step 5

Scan your computer with your Trend Micro product to delete files detected as RANSOM_WHITEROSE.THDOBAH. 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 the following Trend Micro Support pages for more information:

Step 6

Restore encrypted files from backup.


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