RANSOM_CRYPTRITU.B
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 component file(s):
- %Application Data%\Romhubmil Rurhov\Romhubmil.exe (Main component responsible for ransomware routine)
- %Application Data%\Romhubmil Rurhov\uh0aoFUs9BRhT
- %Application Data%\Romhubmil Rurhov\.Romhubmil\lock
- %Application Data%\Romhubmil Rurhov\.Romhubmil\state.tmp
- %Application Data%\Romhubmil Rurhov\.Romhubmil\state
- %Application Data%\Romhubmil Rurhov\.Romhubmil\unverified-microdesc-consensus.tmp
- %Application Data%\Romhubmil Rurhov\.Romhubmil\unverified-microdesc-consensus
- %Application Data%\Romhubmil Rurhov\.Romhubmil\cached-certs.tmp
- %Application Data%\Romhubmil Rurhov\.Romhubmil\cached-certs
- %Application Data%\Romhubmil Rurhov\.Romhubmil\unverified-microdesc-consensus
- %Application Data%\Romhubmil Rurhov\.Romhubmil\cached-microdesc-consensus.tmp
- %Application Data%\Romhubmil Rurhov\.Romhubmil\cached-microdesc-consensus
- %Application Data%\Romhubmil Rurhov\.Romhubmil\cached-microdescs.new
- %Application Data%\Romhubmil Rurhov\.Romhubmil\cached-descriptors.new
- %Application Data%\Romhubmil Rurhov\Application\Romhubmil.exe (TOR client used for communication)
- %Application Data%\Romhubmil Rurhov\Application\Rurhov.exe (TOR component used for communication)
- %Application Data%\Romhubmil Rurhov\.Romhubmil\cached-descriptors.new
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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 creates the following folders:
- %Application Data%\Romhubmil Rurhov
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)
Autostart Technique
This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- %User Startup%\Romhubmil.lnk
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Toolbar
Locked = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\AuthRoot\Certificates\
D4DE20D05E66FC53FE1A50882C78DB2852CAE474
Blob = "{certificate}"
Information Theft
This Trojan accepts the following parameters:
- rjXDdrGUAyZGZSx2W 3468
(Note: This is required to properly run the sample)
Other Details
This Trojan connects to the following website to send and receive information:
- www.ue3kb5u4ckzfqwfjb6yc4.com
It encrypts files with the following extensions:
- *.jpg
- *.jpeg
- *.raw
- *.tif
- *.gif
- *.png
- *.bmp
- *.3dm
- *.max
- *.accdb
- *.db
- *.dbf
- *.mdb
- *.pdb
- *.sql
- *.*sav*
- *.*spv*
- *.*grle*
- *.*mlx*
- *.*sv5*
- *.*game*
- *.*slot*
- *.dwg
- *.dxf
- *.c
- *.cpp
- *.cs
- *.h
- *.php
- *.asp
- *.rb
- *.java
- *.jar
- *.class
- *.aaf
- *.aep
- *.aepx
- *.plb
- *.prel
- *.prproj
- *.aet
- *.ppj
- *.psd
- *.indd
- *.indl
- *.indt
- *.indb
- *.inx
- *.idml
- *.pmd
- *.xqx
- *.xqx
- *.ai
- *.eps
- *.ps
- *.svg
- *.swf
- *.fla
- *.as3
- *.as
- *.txt
- *.doc
- *.dot
- *.docx
- *.docm
- *.dotx
- *.dotm
- *.docb
- *.rtf
- *.wpd
- *.wps
- *.msg
- *.xls
- *.xlt
- *.xlm
- *.xlsx
- *.xlsm
- *.xltx
- *.xltm
- *.xlsb
- *.xla
- *.xlam
- *.xll
- *.xlw
- *.ppt
- *.pot
- *.pps
- *.pptx
- *.pptm
- *.potx
- *.potm
- *.ppam
- *.ppsx
- *.ppsm
- *.sldx
- *.sldm
- *.wav
- *.mp3
- *.aif
- *.iff
- *.m3u
- *.m4u
- *.mid
- *.mpa
- *.wma
- *.ra
- *.avi
- *.mov
- *.mp4
- *.3gp
- *.mpeg
- *.3g2
- *.asf
- *.asx
- *.flv
- *.mpg
- *.wmv
- *.vob
- *.m3u8
- *.csv
- *.efx
- *.sdf
- *.vcf
- *.xml
- *.ses
- *.dat
It does the following:
- It executes the following command:
- Application\Romhubmil.exe --ignore-missing-torrc SOCKSPort 127.0.0.1:85 DataDirectory ./.Romhubmil UseBridges 1 Bridge "meek 0.0.2.0:1 url=https://meek-reflect.appspot.com/ front=www.google.com" Bridge "meek 0.0.2.0:2 url=http://nt.7433.eu.org/0/?url=L21vYy50b3BzcHBhLnRjZWxmZXIta2VlbS8vQTMlc3B0dGg= front=www.google.com" Bridge "meek 0.0.2.0:3 url=https://d2zfqthxsdq309.cloudfront.net/ front=a0.awsstatic.com" Bridge "meek 0.0.2.0:4 url=https://az786092.vo.msecnd.net/ front=ajax.aspnetcdn.com" ClientTransportPlugin "meek exec Application\Rurhov.exe
NOTES:
After its encryption routine, this malware displays the following Window containing ransom notes and information on how to recover the encrypted files:
![](http://documents.trendmicro.com/images/RANSOM_CRYPTRITU_B1.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_CURRENT_USER\Software\Microsoft\Internet Explorer\Toolbar
- Locked = "1"
- Locked = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\AuthRoot\Certificates\D4DE20D05E66FC53FE1A50882C78DB2852CAE474
- Blob = "{certificate}"
- Blob = "{certificate}"
Step 5
Search and delete these folders
- %Application Data%\Romhubmil Rurhov
Step 6
Search and delete these files
- %User Startup%\Romhubmil.lnk
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_CRYPTRITU.B. 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 8
Restore encrypted files from backup.
Step 9
Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYPTRITU.B. 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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