RANSOM_BTCWARE.X

August 18, 2017
 Analysis by: Martin Xavier Co
 ALIASES:

Ransom:Win32/Ergop.A (Microsoft); Ransom.CryptXXX (Sophos)

 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:

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 executes then deletes itself afterward.

It encrypts files with specific file extensions.

  TECHNICAL DETAILS

File Size:

258,048 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

01 Aug 2017

Payload:

Drops files, Terminates processes, Encrypts 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 files:

  • {folder of encrypted files}\!back_files!.html
  • %Desktop%\!back_files!.html
  • %System Root%\Users\Public\{malware name}
  • %System Root%\Users\Public\{e29ac6c0-7037-11de-816d-806e6f6e6963}
  • %TEMP%\__t{random characters}.tmp.bat

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

It executes then deletes itself afterward.

Autostart Technique

This Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
CertificatesCheck = "%User Profile%\{malware name}"

Process Termination

This Ransomware terminates processes or services that contain any of the following strings if found running in the affected system's memory:

  • sql
  • outlook
  • ssms
  • postgre
  • excel
  • word

Other Details

This Ransomware executes the following command to disable/stop/delete Windows components:

  • vssadmin.exe Delete Shadows /All /Quiet
  • reg delete "HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Default" /va /f
  • reg delete "HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Servers" /f

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .$er
  • .4db
  • .4dd
  • .4d
  • .4mp
  • .abs
  • .abx
  • .accdb
  • .accdc
  • .accde
  • .accdr
  • .accdt
  • .accdw
  • .accft
  • .adn
  • .adp
  • .aft
  • .ahd
  • .alf
  • .ask
  • .awdb
  • .azz
  • .bdb
  • .bib
  • .bnd
  • .bok
  • .btr
  • .cdb
  • .cdb
  • .cdb
  • .ckp
  • .clkw
  • .cma
  • .crd
  • .daconnections
  • .dacpac
  • .dad
  • .dadiagrams
  • .daf
  • .daschema
  • .db
  • .db-shm
  • .db-wa
  • .db2
  • .db3
  • .dbc
  • .dbf
  • .dbf
  • .dbk
  • .dbs
  • .dbt
  • .dbv
  • .dbx
  • .dcb
  • .dct
  • .dcx
  • .dd
  • .df1
  • .dmo
  • .dnc
  • .dp1
  • .dqy
  • .dsk
  • .dsn
  • .dta
  • .dtsx
  • .dx
  • .eco
  • .ecx
  • .edb
  • .emd
  • .eq
  • .fcd
  • .fdb
  • .fic
  • .fid
  • .fi
  • .fm5
  • .fmp
  • .fmp12
  • .fmps
  • .fo
  • .fp3
  • .fp4
  • .fp5
  • .fp7
  • .fpt
  • .fzb
  • .fzv
  • .gdb
  • .gwi
  • .hdb
  • .his
  • .ib
  • .idc
  • .ihx
  • .itdb
  • .itw
  • .jtx
  • .kdb
  • .lgc
  • .maq
  • .mdb
  • .mdbhtm
  • .mdf
  • .mdn
  • .mdt
  • .mrg
  • .mud
  • .mwb
  • .myd
  • .ndf
  • .ns2
  • .ns3
  • .ns4
  • .nsf
  • .nv2
  • .nyf
  • .oce
  • .odb
  • .oqy
  • .ora
  • .orx
  • .owc
  • .owg
  • .oyx
  • .p96
  • .p97
  • .pan
  • .pdb
  • .pdm
  • .phm
  • .pnz
  • .pth
  • .pwa
  • .qpx
  • .qry
  • .qvd
  • .rctd
  • .rdb
  • .rpd
  • .rsd
  • .sbf
  • .sdb
  • .sdf
  • .spq
  • .sqb
  • .sq
  • .sqlite
  • .sqlite3
  • .sqlitedb
  • .str
  • .tcx
  • .tdt
  • .te
  • .teacher
  • .tmd
  • .trm
  • .udb
  • .usr
  • .v12
  • .vdb
  • .vpd
  • .wdb
  • .wmdb
  • .xdb
  • .xld
  • .xlgc
  • .zdb
  • .zdc

It avoids encrypting files with the following strings in their file name:

  • !back_files!.html
  • {e29ac6c0-7037-11de-816d-806e6f6e6963}
  • .ocean

It avoids encrypting files with the following strings in their file path:

  • Windows
  • Microsoft
  • Microsoft Help
  • Windows App Certification Kit
  • Windows Defender
  • ESET
  • COMODO
  • Windows NT
  • Windows Kits
  • Windows Mail
  • Windows Media Player
  • Windows Multimedia Platform
  • Windows Phone Kits
  • Windows Phone Silverlight Kits
  • Windows Photo Viewer
  • Windows Portable Devices
  • Windows Sidebar
  • WindowsPowerShell
  • Temp
  • NVIDIA Corporation
  • Microsoft.NET
  • Internet Explorer
  • Kaspersky Lab
  • McAfee
  • Avira
  • spytech software
  • sysconfig
  • Avast
  • Dr.Web
  • Symantec
  • Symantec_Client_Security
  • system volume information
  • AVG
  • Microsoft Shared
  • Common Files
  • Outlook Express
  • Movie Maker
  • Chrome
  • Mozilla Firefox
  • Opera
  • YandexBrowser
  • ntldr
  • Wsus
  • ProgramData

It appends the following extension to the file name of the encrypted files:

  • {original filename}.ocean

It leaves text files that serve as ransom notes containing the following text:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.568.08

FIRST VSAPI PATTERN DATE:

01 Aug 2017

VSAPI OPR PATTERN File:

13.569.00

VSAPI OPR PATTERN Date:

02 Aug 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

Scan your computer with your Trend Micro product to delete files detected as RANSOM_BTCWARE.X. 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 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.  
  • %Desktop%\!back_files!.html
  • %System Root%\Users\Public\{malware name}
  • %System Root%\Users\Public\{e29ac6c0-7037-11de-816d-806e6f6e6963}
  • %TEMP%\__t{random characters}.tmp.bat

Step 5

Delete this 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\RunOnce
    • CertificatesCheck = "%User Profile%\{malware name}"

Step 6

Restore encrypted files from backup.


Did this description help? Tell us how we did.