TROJ_CRILOCK.YMY

August 18, 2014
 Modified by: Rhena Inocencio
 ALIASES:

Ransom:Win32/Crilock.D (Microsoft)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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, Dropped by other malware

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 connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

204,800 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

31 Jul 2014

Payload:

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:

  • %Windows%\{random filename}.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

It adds the following processes:

  • explorer.exe

It injects itself into the following processes as part of its memory residency routine:

  • explorer.exe

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
{random name} = "%Windows%\{random filename}.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Bit Torrent Application\
Configuration
02000000 = "%Windows%\{random filename}.exe"

HKEY_CURRENT_USER\Software\Bit Torrent Application\
Configuration
01000000 = "{binary copy of itself}"

Information Theft

This Trojan gathers the following data:

  • Machine GUID
  • Computer name

Other Details

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

  • https://{BLOCKED}dgewiki.info/gate.php

NOTES:

This Trojan connects to the URL above to download the key used in encrypting the files.

It encrypts the following files and appends ".encrypted" to them:

  • wb2
  • psd
  • p7c
  • p7b
  • p12
  • pfx
  • pem
  • crt
  • cer
  • der
  • pl
  • py
  • lua
  • css
  • js
  • asp
  • php
  • incpas
  • asm
  • hpp
  • cpp
  • 7z
  • zip
  • rar
  • drf
  • blend
  • apj
  • 3ds
  • dwg
  • sda
  • ps
  • pat
  • fxg
  • fhd
  • fh
  • dxb
  • drw
  • design
  • ddrw
  • ddoc
  • dcs
  • csl
  • csh
  • cpi
  • cgm
  • cdx
  • cdrw
  • cdr6
  • cdr5
  • cdr4
  • cdr3
  • cdr
  • awg
  • ait
  • ai
  • agd1
  • ycbcra
  • x3f
  • stx
  • st8
  • st7
  • st6
  • st5
  • st4
  • srw
  • srf
  • sr2
  • sd1
  • sd0
  • rwz
  • rwl
  • rw2
  • raw
  • raf
  • ra2
  • ptx
  • pef
  • pcd
  • orf
  • nwb
  • nrw
  • nop
  • nef
  • ndd
  • mrw
  • mos
  • mfw
  • mef
  • mdc
  • kdc
  • kc2
  • iiq
  • gry
  • grey
  • gray
  • fpx
  • fff
  • exf
  • erf
  • dng
  • dcr
  • dc2
  • crw
  • craw
  • cr2
  • cmt
  • cib
  • ce2
  • ce1
  • arw
  • 3pr
  • 3fr
  • mpg
  • jpeg
  • jpg
  • mdb
  • sqlitedb
  • sqlite3
  • sqlite
  • sql
  • sdf
  • sav
  • sas7bdat
  • s3db
  • rdb
  • psafe3
  • nyf
  • nx2
  • nx1
  • nsh
  • nsg
  • nsf
  • nsd
  • ns4
  • ns3
  • ns2
  • myd
  • kpdx
  • kdbx
  • idx
  • ibz
  • ibd
  • fdb
  • erbsql
  • db3
  • dbf
  • db-journal
  • db
  • cls
  • bdb
  • al
  • adb
  • backupdb
  • bik
  • backup
  • bak
  • bkp
  • moneywell
  • mmw
  • ibank
  • hbk
  • ffd
  • dgc
  • ddd
  • dac
  • cfp
  • cdf
  • bpw
  • bgt
  • acr
  • ac2
  • ab4
  • djvu
  • pdf
  • sxm
  • odf
  • std
  • sxd
  • otg
  • sti
  • sxi
  • otp
  • odg
  • odp
  • stc
  • sxc
  • ots
  • ods
  • sxg
  • stw
  • sxw
  • odm
  • oth
  • ott
  • odt
  • odb
  • csv
  • rtf
  • accdr
  • accdt
  • accde
  • accdb
  • sldm
  • sldx
  • ppsm
  • ppsx
  • ppam
  • potm
  • potx
  • pptm
  • pptx
  • pps
  • pot
  • ppt
  • xlw
  • xll
  • xlam
  • xla
  • xlsb
  • xltm
  • xltx
  • xlsm
  • xlsx
  • xlm
  • xlt
  • xls
  • xml
  • dotm
  • dotx
  • docm
  • docx
  • dot
  • doc
  • txt

After successfully encrypting user's files, it drops the ransom note !!READ_THIS!!.html.

It deletes shadow copies by executing the following command:

  • vssadmin.exe Delete Shadows /All /Quiet

It displays the following ransom messages:



  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.956.02

FIRST VSAPI PATTERN DATE:

31 Jul 2014

VSAPI OPR PATTERN File:

10.957.00

VSAPI OPR PATTERN Date:

01 Aug 2014

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 and note files detected as TROJ_CRILOCK.YMY

Step 4

Restart in Safe Mode

[ Learn More ]

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {random name} = "%Windows%\{random filename}.exe"
  • In HKEY_CURRENT_USER\Software\Bit Torrent Application\Configuration
    • 02000000 = "%Windows%\{random filename}.exe"
  • In HKEY_CURRENT_USER\Software\Bit Torrent Application\Configuration
    • 01000000 = "{binary copy of itself}"

Step 6

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.
  • !!READ_THIS!!.html

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CRILOCK.YMY. 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:
Step 8

Restore the modified files from backup.


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