RANSOM_CRYPDNC.A

 Analysis by: Marvelous Pelin

 ALIASES:

Ransom.DoNotChange(Malwarebytes)

 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.

  TECHNICAL DETAILS

File Size:

712,704 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

30 Mar 2017

Payload:

Drops files, 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:

  • %All Users Profile%\A.txt - list of encrypted files
  • %All Users Profile%\A2.txt - list of encrypted files
  • {folder of encrypted files}\HOW TO DECODE FILES!!!.txt - ransom note
  • {folder of encrypted files}\КАК РАСШИФРОВАТЬ ФАЙЛЫ!!! - ransom note in russian language
  • %User Temp%\~.bat - delete itself and shutdown the infected machine after 1 minute

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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 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.)

Other Details

This Ransomware renames encrypted files using the following names:

  • {original filename and extension}.id-7ES642406.cry

It does the following:

  • It executes the following commands:
    • cmd.exe /c %System%\icacls.exe "c:\System Volume Information" /grant {username}:F
    • cmd.exe /c %System%\icacls.exe "c:\System Volume Information" /remove {username}
    • cmd.exe /c %System%\icacls.exe "d:\System Volume Information" /grant {username}:F
    • cmd.exe /c %System%\icacls.exe "d:\System Volume Information" /remove {username}
  • It also encrypts files with file size greater than 1,800,000 bytes and does not have any of the following extensions:
    • .cry
    • .dll
    • .iso
    • .tmp
    • .ypt
  • It encrypts files with file size greater than 9000 bytes and has any of the following extensions:
    • .1cd
    • .3dp
    • .3gp
    • .7z
    • .abk
    • .abs
    • .accdb
    • .as
    • .ate
    • .avi
    • .bac
    • .backu
    • .bak
    • .bin
    • .bkc
    • .bkf
    • .bkp
    • .bls
    • .bpn
    • .c
    • .cab
    • .cbk
    • .cbu
    • .cdd
    • .cdr
    • .cdw
    • .cdx
    • .cer
    • .cf
    • .cfu
    • .cgm
    • .ck9
    • .cmx
    • .cpp
    • .cpt
    • .cs
    • .csr
    • .csv
    • .dat
    • .db
    • .db2
    • .db3
    • .dba
    • .dbc
    • .dbf
    • .dbk
    • .dbs
    • .dbt
    • .dbv
    • .dbx
    • .dcb
    • .dd
    • .ddl
    • .dds
    • .df1
    • .dgn
    • .dmo
    • .doc
    • .docm
    • .docx
    • .dp1
    • .dt
    • .dwg
    • .dxf
    • .dxl
    • .eap
    • .eco
    • .edb
    • .emd
    • .eml
    • .epf
    • .eps
    • .eql
    • .erf
    • .ert
    • .ext
    • .fbf
    • .fbu
    • .fcd
    • .fh
    • .flb
    • .flkb
    • .frf
    • .frm
    • .frm
    • .frx
    • .gdb
    • .gpx
    • .gzip
    • .hdr
    • .htm
    • .html
    • .igs
    • .java
    • .jpeg
    • .jpg
    • .jse
    • .json
    • .jsp
    • .key
    • .ldf
    • .mac
    • .md
    • .mdb
    • .mdf
    • .mdx
    • .mft
    • .mp4
    • .mpeg
    • .msf
    • .msg
    • .mxl
    • .myd
    • .myi
    • .nam
    • .nb7
    • .nbd
    • .nbk
    • .nbs
    • .ncb
    • .nch
    • .ndoc
    • .nofiles
    • .npf
    • .ns2
    • .ns3
    • .ns4
    • .nyf
    • .obkp
    • .ods
    • .odt
    • .old
    • .one
    • .ora
    • .pan
    • .pas
    • .pdb
    • .pdf
    • .pdm
    • .pdn
    • .phm
    • .pl
    • .png
    • .pps
    • .ppsm
    • .ppt
    • .pptm
    • .pptx
    • .ps
    • .psd
    • .pst
    • .py
    • .rar
    • .ref
    • .reg
    • .rsd
    • .rtf
    • .sai
    • .sbb
    • .sbf
    • .sdb
    • .sdf
    • .sqb
    • .sql
    • .sqlite
    • .sqlite3
    • .sqlitedb
    • .svg
    • .tar
    • .tbb
    • .tbn
    • .tdt
    • .te
    • .tib
    • .txt
    • .uci
    • .udb
    • .usr
    • .vbe
    • .vbp
    • .vbs
    • .vbx
    • .vhd
    • .vmdk
    • .vrp
    • .xds
    • .xld
    • .xls
    • .xlsm
    • .xlsx
    • .xml
    • .zip
  • It executes the following commands to stop services:
    • net stop "MSSQLSERVER" /y
    • net stop "MSSQL$SQL" /y
    • net stop "MSSQL$SQLEXPRESS" /y
    • net stop "postgresql-x64-9.6" /y
    • net stop "Schedule" /y
    • net stop "RKeeperMidServer" /y
    • net stop "RKeeperRepServer" /y
    • net stop "SDBSERV" /y
    • net stop "SQLWriter" /y
    • net stop "TeamViewer" /y
    • net stop "hMailServer" /y
    • net stop "MySQL" /y
    • net stop "MSSQL$S15292784" /y
    • net stop "SQLBrowser" /y
    • net stop "FileZilla Server" /y
    • net stop "RServer3" /y
    • net stop "afcdpsrv" /y
    • net stop "syncagentsrv" /y
    • net stop "C__UCS_CARDSERV_CARDSERV" /y
    • net stop "Sdbserv 192.168.0.18" /y
    • net stop "tvnserver" /y
    • net stop "SrvSgr030" /y
    • net stop "GbpSv" /y
    • net stop "uvnc_service" /y
    • net stop "MSSQL$MEGASUL" /y
    • net stop "fbguard" /y
    • net stop "fbserver" /y
    • net stop "D_RK6CARDSERV_CARDSERV" /y
    • net stop "acrSch2Svr" /y
    • net stop "acrSch2Svr" /y

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

NOTES:

The ransom notes contains the following:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.308.06

FIRST VSAPI PATTERN DATE:

30 Mar 2017

VSAPI OPR PATTERN File:

13.309.00

VSAPI OPR PATTERN Date:

31 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 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.  
  • %All Users Profile%\A.txt
  • %All Users Profile%\A2.txt
  • {folder of encrypted files}\HOW TO DECODE FILES!!!.txt
  • {folder of encrypted files}\КАК РАСШИФРОВАТЬ ФАЙЛЫ!!!
  • %User Temp%\~.bat

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_CRYPDNC.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 6

Restore encrypted files from backup.


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