TROJ_CRILOCK.SM4
Ransom:Win32/Teerac.A(Microsoft), Win32/Filecoder.DI trojan(Eset)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 connects to certain websites to send and receive information.
TECHNICAL DETAILS
454,144 bytes
EXE
Yes
16 Oct 2014
Connects to URLs/IPs, Steals information, Displays message/message boxes, 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:
- %All Users Profile%\Application Data\{random folder name}\01000000
- %Windows%\{random 8 letters}.exe
(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.. %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}\02000000
- %All Users Profile%\Application Data\{random folder name}\03000000 - 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 creates the following folders:
- %All Users Profile%\Application Data\{random folder name}
(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 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_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random 8 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:
- {BLOCKED}atic.ru:443/topic.php
- http://octoberpics.ru/topic.php
It encrypts files with the following extensions:
- 3ds
- 3fr
- 3pr
- 7z
- ab4
- ac2
- accdb
- accde
- accdr
- accdt
- acr
- adb
- agd1
- ai
- ait
- al
- apj
- arw
- asm
- asp
- bak
- bdb
- bgt
- bik
- bkp
- blend
- bpw
- cdf
- cdr
- cdr3
- cdr4
- cdr5
- cdr6
- cdrw
- cdx
- ce1
- ce2
- cer
- cfp
- cgm
- cib
- cls
- cmt
- cpi
- cpp
- cr2
- craw
- crt
- crw
- csh
- csl
- css
- csv
- dac
- db
- db-journal
- db3
- dbf
- dc2
- dcr
- dcs
- ddd
- ddoc
- ddrw
- der
- design
- dgc
- djvu
- dng
- doc
- docm
- docx
- dot
- dotm
- dotx
- drf
- drw
- dwg
- dxb
- erbsql
- erf
- exf
- fdb
- ffd
- fff
- fh
- fhd
- fpx
- fxg
- gray
- grey
- gry
- hbk
- hpp
- ibank
- awg
- backup
- backupdb
- ibd
- ibz
- idx
- iiq
- incpas
- jpeg
- jpg
- js
- kc2
- kdbx
- kdc
- kpdx
- lua
- mdb
- mdc
- mef
- mfw
- mmw
- moneywell
- mos
- mpg
- mrw
- myd
- ndd
- nef
- nop
- nrw
- ns2
- ns3
- ns4
- nsd
- nsf
- nsg
- nsh
- nwb
- nx1
- nx2
- nyf
- odb
- odf
- odg
- odm
- odp
- ods
- odt
- orf
- otg
- oth
- otp
- ots
- ott
- p12
- p7b
- p7c
- pat
- pcd
- pef
- pem
- pfx
- php
- pl
- pot
- potm
- potx
- ppam
- pps
- ppsm
- ppsx
- ppt
- pptm
- pptx
- ps
- psafe3
- psd
- ptx
- py
- ra2
- raf
- rar
- raw
- rdb
- rtf
- rw2
- rwl
- rwz
- s3db
- sas7bdat
- sav
- sd0
- sd1
- sda
- sdf
- sldm
- sldx
- sql
- sqlite
- sqlite3
- sqlitedb
- sr2
- srf
- srw
- st4
- st5
- st6
- st7
- st8
- stc
- std
- sti
- stw
- stx
- sxc
- sxd
- sxg
- sxi
- sxm
- sxw
- txt
- wb2
- x3f
- xla
- xlam
- xll
- xlm
- xls
- xlsb
- xlsm
- xlsx
- xlt
- xltm
- xltx
- xlw
- xml
- ycbcra
- zip
It renames encrypted files using the following names:
- {original file name and extension}.encrypted
NOTES:
This Trojan connects to the website {BLOCKED}c.ru:443/topic.php to send and receive information.
It drops the ransom note DECRYPT_INSTRUCTIONS.html to every folder it encrypts. It deletes shadow copies by executing the following command:
vssadmin.exe Delete Shadows /All /Quiet
It displays the following ransom message:
SOLUTION
9.700
11.218.05
17 Oct 2014
11.219.00
17 Oct 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
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random 8 letters} = "%Windows%\{random 8 letters}.exe"
- {random 8 letters} = "%Windows%\{random 8 letters}.exe"
Step 5
Search and delete these folders
- %All Users Profile%\Application Data\{random folder name}
Step 6
Search and delete these files
- DECRYPT_INSTRUCTIONS.html
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CRILOCK.SM4. 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. Note that the encrypted files have the extension .encrypted.
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