Arrival Details
This Ransomware 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 Ransomware drops and executes the following files:
- %Application Data%\nlo.exe -> copy of itself
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.)
It drops the following non-malicious files:
- %User Temp%\1.png
- %User Temp%\2.png
- %User Temp%\Screen.jpg ->screen capture of the affected system
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
Autostart Technique
This Ransomware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
JOJA = %Application Data%\nlo.exe
Other System Modifications
This Ransomware adds the following registry entries:
HKEY_CURRENT_USER\Software
MOI = {67 random digits} -> deleted once files have been encrypted
HKEY_CURRENT_USER\Software
1 = 1
It sets the system's desktop wallpaper to the following image:
- %User Temp%\2.png
Information Theft
This Ransomware gathers the following information on the affected computer:
- Volume Serial Number
- Running Processes
- Machine Name
Stolen Information
This Ransomware sends the data it gathers to the following email addresses via SMTP:
- Host: auth.smtp.1and1.fr
- Email address: {BLOCKED}24@gmail.com
Other Details
This Ransomware does the following:
- It encrypts files in all available drives
- It sleeps when it finds AvastSvc process running in the affected computer
- The email it sends out contains the following:
- Subject:
V3.1 New Client {Volume Serial Number} - Body:
"------Process List------\r\n{process 1} | \r\n{process 2} | ... | \r\n------------------------\r\nSerial Number: {67 random numbers}" - Attachment:
Screen capture (%User Temp%\Screen.jpg) - From:
{BLOCKED}c@sagform.fr "{Machine Name}"
- It displays the following:
- Encrypted files contain a ransom note prepended before the actual encrypted file:
Ransomware Routine
This Ransomware avoids encrypting files with the following strings in their file name:
- boot.ini
- autoexec.bat
- Bootfont.bin
- config.sys
- io.sys
- msdos.sys
- ntdetect.com
- ntldr
- pagefile.sys
- desktop.ini
- Google Chrome.lnk
- Mozilla Firefox.lnk
- Internet Explorer.lnk
- Locker.exe
- .css
It avoids encrypting files with the following strings in their file path:
It renames encrypted files using the following names:
It drops the following file(s) as ransom note:
- %Desktop%\Comment débloquer mes fichiers .txt
- %User Startup%\Readme.txt
however the malware encountered an exception in its code while writing the contents of the note, hence these files contain nothing
(Note: %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista, 7, and 8.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)
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
Identify and terminate files detected as Ransom.Win32.JOBCRYPTER.THOAAGAI
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- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
To terminate the malware/grayware/spyware process:
- Scan your computer with your Trend Micro product and take note of the name of the malware/grayware/spyware detected.
- Open Windows Task Manager. To do this, press CTRL+SHIFT+ESC.
- View the list of all running programs. To do this:
• For Windows 2000, XP, Server 2003, Vista, 7 and Server 2008 users, click the Processes tab.
• For Windows 8, 8.1 and Server 2012 users, click the Details tab. - In the list of running programs, locate a malware/grayware/spyware file detected earlier.
- Select the detected files, then press either the End Task or the End Process button, depending on the version of Windows you are using.
- Do the same for the remaining detected malware/grayware/spyware files in the list of running programs.
- To check if the malware/grayware/spyware process has been terminated, close Task Manager, and then open it again.
- Close Task Manager.
Step 4
Delete this registry value
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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
- JOJA = "%Application Data%\nlo.exe"
- In HKEY_CURRENT_USER\Software
To delete the registry value this malware created:
- Open Registry Editor. To do this:
» For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run, type regedit in the text box provided, and then press Enter.
» For Windows Vista, Windows 7, and Windows Server 2008 users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
JOJA = "%Application Data%\nlo.exe" - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software - In the right panel, locate and delete the entry:
1 = 1 - Close Registry Editor.
Step 5
Search and delete this file
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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%\1.png
- %User Temp%\2.png
- %User Temp%\Screen.jpg
- %Desktop%\Comment débloquer mes fichiers .txt
- %User Startup%\Readme.txt
To manually delete a malware/grayware file from an affected system:
• For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the File name* input box, type the following:
- %User Temp%\1.png
- %User Temp%\2.png
- %User Temp%\Screen.jpg
- %Desktop%\Comment débloquer mes fichiers .txt
- %User Startup%\Readme.txt
- In the Look In drop-down list, select My Computer then press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).
• For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
- In the Search Computer/This PC input box, type:
- %User Temp%\1.png
- %User Temp%\2.png
- %User Temp%\Screen.jpg
- %Desktop%\Comment débloquer mes fichiers .txt
- %User Startup%\Readme.txt
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 6
Reset your Desktop properties
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To restore your wallpaper:
- Click Start>Settings>Control Panel.
- Double-click the Display option and click the Background tab.
- Click the Browse button to select your preferred wallpaper or select an image from the Windows built-in wallpapers.
- Choose OK to apply the changes.
Step 7
Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.JOBCRYPTER.THOAAGAI. 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 the following Trend Micro Support pages for more information:
Step 8
Restore encrypted files from backup.
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