TROJ_CRILOCK.YNG
Ransom:Win32/Teerac (Microsoft); Trojan-Ransom.Win32.Cryptolocker.cg (Kaspersky); Trojan-Ransom.Win32.Cryptolocker (Ikarus); Win32/Filecoder.DI (ESET-NOD32)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This Trojan is a CryptoLocker variant that uses Tor to hide its network activity. This specific variant is found as an attachment to spammed email with an Italian message.
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
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 8 letters}.exe
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It drops the following file(s)/component(s):
- %All Users Profile%\Application Data\{random folder name}\00000000
- %All Users Profile%\Application Data\{random folder name}\01000000 ← encrypted copy of itself
- %All Users Profile%\Application Data\{random folder name}\02000000
- %All Users Profile%\Application Data\{random folder name}\03000000 ← encrypted copy of ransom note
- %All Users Profile%\Application Data\{random folder name}\04000000
(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.)
It adds the following processes:
- explorer.exe
It injects codes into the following process(es):
- created 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 letters} = "%Windows%\{random 8 letters}.exe"
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:
- http://{BLOCKED}pics.ru/topic.php
It encrypts files with the following extensions:
- wb2
- psd
- p7c
- p7b
- p12
- pfx
- pem
- crt
- cer
- der
- pl
- py
- lua
- css
- js
- asp
- php
- incpas
- asm
- hpp
- h
- cpp
- c
- 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
- 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
It renames encrypted files using the following names:
- {original file name and extension}.encrypted
NOTES:
This Trojan drops the ransom note DECRYPT_INSTRUCTIONS.html to every directory it encrypts. It deletes shadow copies by executing the following command:
vssadmin.exe Delete Shadows /All /Quiet
It displays the following ransom message:
![](http://www.trendmicro.com/vinfo/resources/images/TROJ_CRILOCK_YNG_img1.jpg)
![](http://www.trendmicro.com/vinfo/resources/images/TROJ_CRILOCK_YNG_img2.jpg)
SOLUTION
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
Step 4
Delete this registry value
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 letters} = "%Windows%\{random 8 letters}.exe"
- {random letters} = "%Windows%\{random 8 letters}.exe"
Step 5
Search and delete this file
- %All Users Profile%\Application Data\{random folder name}\00000000
- %All Users Profile%\Application Data\{random folder name}\01000000
- %All Users Profile%\Application Data\{random folder name}\02000000
- %All Users Profile%\Application Data\{random folder name}\03000000
- %All Users Profile%\Application Data\{random folder name}\04000000
- DECRYPT_INSTRUCTIONS.html
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CRILOCK.YNG. 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.
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