RANSOM_CRYPICH.E

 Analysis by: Mar Philip Elaurza

 ALIASES:

Ransom:Win32/Criakl.D (Microsoft); Trojan-Ransom.Win32.Cryakl.ado (Kaspersky); Ransom.TeslaCrypt (Malwarebytes);

 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:

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 modifies the Internet Explorer Zone Settings.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

365,872 bytes

File Type:

EXE

File Compression:

PECompact

Memory Resident:

No

Initial Samples Received Date:

02 Nov 2015

Payload:

Displays graphics/image, Connects to URLs/IPs, Steals information, 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.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %User Temp%\{malware file name}.{malware file extension}

(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.)

It drops the following files:

  • %User Temp%\desk.jpg
  • %User Temp%\desk.bmp
  • %Program Files%\{random file name}.{random file extension} - contains data to be sent to the C&C
  • %User Temp%\ZDAVX.bat - deletes %User Temp%\{malware file name}.{malware file extension} and deletes itself afterwards

(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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It drops the following copies of itself into the affected system:

  • %Program Files%\{malware file name}.{malware file extension}

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

Autostart Technique

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

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
pr = "%Program Files%\{malware file name}.{malware file extension}"

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_LOCAL_MACHINE\Control Panel\Desktop
TileWallpaper = "0"

(Note: The default value data of the said registry entry is "{User Preference}".)

HKEY_LOCAL_MACHINE\Control Panel\Desktop
Wallpaper = "%User Temp%\desk.bmp"

(Note: The default value data of the said registry entry is "{User Preference}".)

It sets the system's desktop wallpaper to the following image:

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Information Theft

This Trojan gathers the following data:

  • Computer name
  • Machine GUID

Other Details

This Trojan connects to the following website to send and receive information:

  • http://{BLOCKED}tekhno.com/inst.php

It encrypts files with the following extensions:

  • accdb
  • abf
  • a3d
  • asm
  • fbx
  • fbw
  • fbk
  • fdb
  • fbf
  • max
  • m3d
  • dbf
  • ldf
  • keystore
  • iv2i
  • gbk
  • gho
  • sn1
  • sna
  • spf
  • sr2
  • srf
  • srw
  • tis
  • tbl
  • x3f
  • ods
  • pef
  • pptm
  • txt
  • pst
  • ptx
  • pz3
  • mp3
  • odp
  • qic
  • wps
  • r3d
  • rwl
  • rx2
  • p12
  • sbs
  • sldasm
  • wps
  • sldprt
  • odc
  • odb
  • old
  • nbd
  • nx1
  • nrw
  • orf
  • ppt
  • mov
  • mpeg
  • csv
  • mdb
  • cer
  • arj
  • ods
  • mkv
  • avi
  • odt
  • pdf
  • docx
  • gzip
  • m2v
  • cpt
  • raw
  • cdr
  • cdx
  • 1cd
  • 3gp
  • 7z
  • rar
  • db3
  • zip
  • xlsx
  • xls
  • rtf
  • doc
  • jpeg
  • jpg

It renames encrypted files using the following names:

  • email-ninja.gaiver@aol.com.ver-CL 1.0.0.0.id-{content of %Program Files%\{random file name}.{random file extension}}.randomname-{random strings}.cbf

NOTES:

This Trojan traverses the following drives to encrypt files:

  • d:\
  • e:\
  • f:\
  • g:\
  • h:\
  • i:\
  • j:\
  • k:\
  • l:\
  • m:\
  • n:\
  • o:\
  • q:\
  • r:\
  • s:\
  • t:\
  • u:\
  • v:\
  • w:\
  • x:\
  • y:\
  • z:\

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.118.05

FIRST VSAPI PATTERN DATE:

29 Oct 2015

VSAPI OPR PATTERN File:

12.119.00

VSAPI OPR PATTERN Date:

30 Oct 2015

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

Reset your Desktop properties

[ Learn More ]

Step 4

Reset Internet security settings

[ Learn More ]

Step 5

Search and delete these files

[ 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%\desk.jpg
  • %User Temp%\desk.bmp
  • %Program Files%\{random file name}.{random file extension}
  • %User Temp%\ZDAVX.bat

Step 6

Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYPICH.E. 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.

NOTES:

Restore the encrypted files by this malware from backup.


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