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RANSOM_HIDDENTEARZORRO.A

March 31, 2017
 Analysis by: Marvelous Pelin
 ALIASES:

Trojan.Ransom.Zorro.A(BitDefender)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

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 connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size:

60,943 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

23 Mar 2017

Payload:

Encrypts files, Connects to URLs/IPs, Drops files

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 copies of itself into the affected system and executes them:

  • %Application Data%\Microsoft\svchost.exe

(Note: %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 drops the following files:

  • %User Temp%\melt.txt - contains malware full path
  • %User Profile%\Documents\l\{user name} passcode.txt - contains gathered information

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.. %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.)

It drops and executes the following files:

  • %User Profile%\shwdFtY8245PqWQWf.bat - used to delete shadow copies
  • %User Profile%\Take_Seriously (Your saving grace).txt - 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.)

It creates the following folders:

  • %User Profile%\Documents\l

(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 Ransomware modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

(Note: The default value data of the said registry entry is {user preference}.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 1

(Note: The default value data of the said registry entry is {user preference}.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoWindowsUpdate = 1

(Note: The default value data of the said registry entry is {user preference}.)

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\SystemRestore
DisableSR = 1

(Note: The default value data of the said registry entry is {user preference}.)

Backdoor Routine

This Ransomware connects to the following websites to send and receive information:

  • ftp://ftp.{BLOCKED}q.com.plenty{filename of each textfile}

Information Theft

This Ransomware gathers the following data:

  • Data from text files (files with .txt extension) in all directories
  • Username
  • PC name
  • OS name
  • OS version
  • OS platform

Other Details

This Ransomware encrypts files with the following extensions:

  • .1
  • .10
  • .11
  • .12
  • .13
  • .14
  • .15
  • .16
  • .17
  • .18
  • .19
  • .1cd
  • .2
  • .20
  • .3
  • .3dm
  • .3Ds
  • .3fr
  • .3g2
  • .3gp
  • .3pr
  • .4
  • .5
  • .6
  • .7
  • .7z
  • .7zip
  • .8
  • .9
  • .aac
  • .ab4
  • .abd
  • .abh
  • .acc
  • .accdb
  • .accde
  • .accdr
  • .accdt
  • .ach
  • .aco
  • .acr
  • .act
  • .adb
  • .adp
  • .ads
  • .aes
  • .aff
  • .aft
  • .agdl
  • .ai
  • .aiff
  • .ait
  • .al
  • .alv
  • .aoi
  • .apj
  • .apk
  • .arw
  • .ascx
  • .asd
  • .asf
  • .asl
  • .asm
  • .asp
  • .aspx
  • .asset
  • .asx
  • .atb
  • .atn
  • .aux
  • .avi
  • .awg
  • .ax
  • .axd
  • .back
  • .backup
  • .backupdb
  • .bak
  • .bank
  • .bay
  • .bdb
  • .bgt
  • .big
  • .bik
  • .bin
  • .bkp
  • .blend
  • .bmp
  • .bpw
  • .bsa
  • .c
  • .c00
  • .c01
  • .c02
  • .c03
  • .c04
  • .c05
  • .c06
  • .c07
  • .c96
  • .c97
  • .c99
  • .cache
  • .cash
  • .cdb
  • .cdf
  • .cdr
  • .cdr3
  • .cdr4
  • .cdr5
  • .cdr6
  • .cdrw
  • .cdx
  • .ce1
  • .ce2
  • .cer
  • .cfg
  • .cfm
  • .cfn
  • .cg
  • .cgm
  • .chm
  • .cib
  • .Class
  • .cls
  • .cmt
  • .conf
  • .config
  • .contact
  • .cpi
  • .cpp
  • .cr2
  • .craw
  • .crt
  • .crw
  • .cry
  • .cs
  • .csh
  • .csh
  • .csl
  • .csproj
  • .css
  • .csv
  • .d3dbsp
  • .dac
  • .das
  • .dat
  • .db
  • .db3
  • .db_journal
  • .dbf
  • .dbrsb
  • .dbrush
  • .dbx
  • .dc2
  • .dcr
  • .dcs
  • .ddd
  • .ddoc
  • .ddrw
  • .dds
  • .def
  • .der
  • .des
  • .design
  • .dgc
  • .dgn
  • .dic
  • .dit
  • .djvu
  • .dng
  • .doc
  • .docm
  • .docx
  • .dot
  • .dotm
  • .dotx
  • .drf
  • .drw
  • .dtd
  • .DTD
  • .dwg
  • .dxb
  • .dxf
  • .dxg
  • .eap
  • .edb
  • .eml
  • .eps
  • .erbsql
  • .erf
  • .ESD
  • .eve
  • .exf
  • .fdb
  • .feed-ms
  • .feedsdb-ms
  • .ffd
  • .fff
  • .fh
  • .fhd
  • .fla
  • .flac
  • .flb
  • .flf
  • .flv
  • .flvv
  • .fon
  • .forge
  • .fp3
  • .fp5
  • .fp5
  • .fp7
  • .fp8
  • .fp9
  • .fpx
  • .full
  • .fxg
  • .gbk
  • .gbr
  • .gho
  • .gif
  • .gitattributes
  • .gitignore
  • .gray
  • .grd
  • .grey
  • .groups
  • .gry
  • .h
  • .h
  • .hbk
  • .hdd
  • .hdt
  • .hlp
  • .hpp
  • .htm
  • .html
  • .ibank
  • .ibd
  • .ibz
  • .ico
  • .idx
  • .iif
  • .iiq
  • .incpas
  • .indd
  • .inf
  • .inf_loc
  • .info
  • .info_
  • .irs
  • .iwi
  • .ja
  • .jar
  • .java
  • .jnt
  • .jpe
  • .jpeg
  • .JPG
  • .jpg
  • .js
  • .json
  • .jsonlz4
  • .jsx
  • .k2p
  • .kc2
  • .kdbx
  • .kdc
  • .key
  • .kpdx
  • .kwm
  • .laccdb
  • .lbf
  • .lck
  • .ldf
  • .list
  • .lit
  • .litemod
  • .litesql
  • .little
  • .lock
  • .log
  • .ltx
  • .lua
  • .m
  • .m2ts
  • .m3u
  • .m4a
  • .m4b
  • .m4p
  • .odp
  • .ods
  • .odt
  • .odt
  • .ogg
  • .oil
  • .old
  • .omg
  • .one
  • .orf
  • .ost
  • .otg
  • .oth
  • .otp
  • .ots
  • .ott
  • .p00
  • .p01
  • .p02
  • .p03
  • .p04
  • .p05
  • .p06
  • .p07
  • .p12
  • .p3e
  • .p3m
  • .p7b
  • .p7c
  • .p7x
  • .p96
  • .p97
  • .p98
  • .pab
  • .pages
  • .pas
  • .pat
  • .pat
  • .pbf
  • .pbk
  • .pcd
  • .pct
  • .pdb
  • .pdd
  • .pdf
  • .pef
  • .pfx
  • .php
  • .php
  • .pif
  • .pl
  • .plc
  • .plus_muhd
  • .pm
  • .pm!
  • .pmi
  • .pmj
  • .pml
  • .pmm
  • .pmo
  • .pmr
  • .pnc
  • .pnd
  • .PNF
  • .PNG
  • .png
  • .pnx
  • .pot
  • .potm
  • .potx
  • .ppam
  • .ppkg
  • .pps
  • .ppsm
  • .ppsx
  • .ppt
  • .pptm
  • .pptx
  • .prf
  • .pri
  • .Private
  • .properties
  • .ps
  • .psafe3
  • .psd
  • .psd
  • .pset
  • .pspimage
  • .pst
  • .ptx
  • .pub
  • .pwm
  • .py
  • .pyc
  • .pyd
  • .qba
  • .qbb
  • .qbm
  • .qbr
  • .qbw
  • .qbx
  • .qby
  • .qcow
  • .qcow2
  • .qdf
  • .qed
  • .qtb
  • .r3d
  • .raf
  • .rar
  • .rat
  • .raw
  • .rdb
  • .re2
  • .re4
  • .resources
  • .resp
  • .resx
  • .rm
  • .rtf
  • .rvt
  • .rw2
  • .rwl
  • .rwz
  • .s3db
  • .safe
  • .sas7bdat
  • .sav
  • .save
  • .say
  • .sbstore
  • .sd0
  • .sda
  • .sdb
  • .sdf
  • .setting
  • .settings
  • .sh
  • .shc
  • .sldm
  • .sldx
  • .slm
  • .sln
  • .small
  • .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
  • .suo
  • .svg
  • .swf
  • .sxc
  • .sxd
  • .sxg
  • .sxi
  • .sxm
  • .sxw
  • .sys
  • .tax
  • .tbb
  • .tbk
  • .tbn
  • .tex
  • .tff
  • .tga
  • .thm
  • .tif
  • .tiff
  • .tlg
  • .tlx
  • .tme
  • .tmp
  • .tpl
  • .ttf
  • .TTF
  • .txt
  • .upk
  • .usr
  • .vb
  • .vbox
  • .vbproj
  • .vbs
  • .vdi
  • .vhd
  • .vhdx
  • .vmdk
  • .vmsd
  • .vmx
  • .vmxf
  • .vob
  • .vpd
  • .vsd
  • .wab
  • .wad
  • .wallet
  • .war
  • .wav
  • .wb2
  • .webm
  • .wma
  • .wmdb
  • .wmf
  • .wmv
  • .wpd
  • .wpl
  • .wps
  • .x11
  • .x3f
  • .xaml
  • .xeml
  • .xis
  • .xla
  • .xlam
  • .xlk
  • .xlm
  • .xlmx
  • .xlr
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .xml
  • .xml
  • .xpi
  • .xpi
  • .xps
  • .xxx
  • .ycbcra
  • .yuv
  • .zap
  • .zip
  • iros
  • .m4p
  • .m4v
  • .ma
  • .mab
  • .manifest
  • .mapimail
  • .max
  • .mbx
  • .md
  • .mdb
  • .mdc
  • .mdf
  • .meek-http-helper
  • .mef
  • .mfw
  • .mht
  • .mid
  • .middle
  • .mkv
  • .mlb
  • .mmw
  • .mnu
  • .mny
  • .money
  • .moneywell
  • .mos
  • .mov
  • .mp3
  • .mp4
  • .mpeg
  • .mpg
  • .mrw
  • .msf
  • .msg
  • .mshi
  • .mts
  • .mui
  • .myapp
  • .myd
  • .nd
  • .ndd
  • .ndf
  • .nef
  • .New
  • .nk2
  • .nop
  • .nrw
  • .ns2
  • .ns3
  • .ns4
  • .nsd
  • .nsf
  • .nsg
  • .nsh
  • .nvram
  • .nwb
  • .nx2
  • .nxl
  • .nyf
  • .oab
  • .obj
  • .odb
  • .odc
  • .odf
  • .odg
  • .odm

It renames encrypted files using the following names:

  • {original filename and extension}.zorro

It does the following:

  • It executes the following command to delete the created copy of itself:
    • cmd.exe /C ping 8.8.8.8 -n 1 -w 2 > Nul & Del %Application Data%\Microsoft\svchost.exe
  • It deletes shadow copies using the following commands:
    • WMIC.exe /C shadowcopy delete
    • vssadmin.exe Delete Shadows /All /Quiet
  • It hides the clock/time on the taskbar

(Note: %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.)

NOTES:

The ransomware displays the following ransom note:

  SOLUTION

Minimum Scan Engine:

9.850

SSAPI PATTERN File:

13.294.02

SSAPI PATTERN Date:

23 Mar 2017

FIRST VSAPI PATTERN FILE:

13.295.00

FIRST VSAPI PATTERN DATE:

24 Mar 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

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Profile%\Documents\l

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 Temp%\melt.txt
  • %User Profile%\Documents\l\{user name} passcode.txt
  • %User Profile%\shwdFtY8245PqWQWf.bat
  • %User Profile%\Take_Seriously (Your saving grace).txt

Step 6

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • From: DisableTaskMgr = 1
      To: DisableTaskMgr = {user preference}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • From: DisableRegistryTools = 1
      To: DisableRegistryTools = {user preference}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • From: NoWindowsUpdate = 1
      To: NoWindowsUpdate = {user preference}
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\SystemRestore
    • From: DisableSR = 1
      To: DisableSR = {user preference}

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_HIDDENTEARZORRO.A. 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 8

Restore encrypted files from backup.


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