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.
It modifies the Internet Explorer Zone Settings.
It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible.
It encrypts files with specific file extensions.
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 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 component file(s):
- %All Users Profile%\Application Data\{Random Folder Name}\{Random File Name 1}
- %All Users Profile%\Application Data\{Random Folder Name}\{Random File Name 3}
- %All Users Profile%\Application Data\{Random Folder Name}\{Random File Name 2}
(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 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 adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\{Random 23 Letters}
- Global\{Random 31 Letters}
It injects codes into the following process(es):
Autostart Technique
This Ransomware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{Random 8 Letters} = "%Windows%\{Random 8 Letters}.exe"
Other System Modifications
This Ransomware adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
EnabledV8 = 0
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
EnabledV9 = 0
Web Browser Home Page and Search Page Modification
This Ransomware modifies the Internet Explorer Zone Settings.
Other Details
This Ransomware connects to the following website to send and receive information:
- http://{BLOCKED}m.com/topic.php
- http://{BLOCKED}k.com/topic.php
It renames encrypted files using the following names:
- {Original Filename}.encrypted
It does the following:
- It deletes shadow copies by executing the following command:
- vssadmin.exe Delete Shadows /All /Quiet
However, as of this writing, the said sites are inaccessible.
Ransomware Routine
This Ransomware encrypts files with the following extensions:
- .avi
- .wav
- .mp3
- .gif
- .ico
- .png
- .bmp
- .txt
- .html
- .inf
- .manifest
- .chm
- .ini
- .tmp
- .log
- .url
- .lnk
- .cmd
- .bat
- .scr
- .msi
- .sys
- .dll
- .exe
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
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To restart in Safe Mode:
• For Windows 2000 users
- Restart your computer.
- Press F8 when you see the Starting Windows bar at the bottom of the screen.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows XP users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Windows Advanced Options menu does not appear, try restarting then pressing F8 several times when the POST screen appears.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows Server 2003 users
- Restart your computer.
- Press F8 after Windows starts up. If the Windows Advanced Options menu does not appear, try restarting again and pressing F8 several times afterward.
- On the Windows Advanced Option menu, use the arrow keys to select Safe Mode then press Enter.
• For Windows Vista, Windows 7, and Windows Server 2008 users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Advanced Boot Options menu does not appear, try restarting and then pressing F8 several times after the POST screen is displayed.
- On the Advanced Boot Options menu, use the arrow keys to select the Safe Mode option, and then press Enter.
• For Windows 8, Windows 8.1, and Windows Server 2012 users
- Access the Charms bar by moving your mouse pointer to the upper right corner of the screen.
- Move your mouse pointer down and click Settings>Change your PC Settings.
- In the left panel, click General.
- In the right panel, scroll down to the bottom to find the Advanced startup section, then click the Restart now button and wait for the system to restart.
- In the Advanced Startup menu, click Troubleshoot>Advanced Options>Startup Settings>Restart and wait for the system to restart.
- In the Startup Settings menu, press 4 to enable safe mode.
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- {Random 8 Letters} = "%Windows%\{Random 8 Letters}.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\PhishingFilter
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\PhishingFilter
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_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
{Random 8 Letters} = "%Windows%\{Random 8 Letters}.exe" - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Internet Explorer>PhishingFilter - In the right panel, locate and delete the entry:
EnabledV8 = 0 - Again In the right panel, locate and delete the entry:
EnabledV9 = 0 - Close Registry Editor.
Step 5
Search and delete these folders
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Please make sure you check the
Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
- %All Users Profile%\Application Data\{Random Folder Name}
To delete malware/grayware/spyware folders:
For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
- In the File name* input box, type:
- %All Users Profile%\Application Data\{Random Folder Name}
- In the Look In drop-down list, select My Computer, then press Enter.
- Once located, select the folder then press SHIFT+DELETE to permanently delete the folder.
- Repeat steps 2 to 4 for the remaining folders:
- %All Users Profile%\Application Data\{Random Folder Name}
*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:
- %All Users Profile%\Application Data\{Random Folder Name}
- Once located, select the file then press SHIFT+DELETE to permanently delete the folder.
- Repeat steps 2-3 for the remaining folders:
- %All Users Profile%\Application Data\{Random Folder Name}
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 6
Search and delete these files
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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.
- %Windows%\{Random 8 Letters}.exe
To delete malware/grayware files:
For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the File name* input box, type
- %Windows%\{Random 8 Letters}.exe
- 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.
- Repeat the said steps for all files listed.
*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:
- %Windows%\{Random 8 Letters}.exe
- Once located, select the file then press SHIFT+DELETE to delete it.
- Repeat the said steps for all files listed.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 7
Reset Internet security settings
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To reset Internet security settings:
- Close all Internet browser windows.
- Open Control Panel. To do this:
• On Windows 2000
Click Start>Settings>Control Panel
• On Windows XP, Server 2003, Vista, and 7
Click Start>Control Panel - Double-click Internet Options.
- In the Internet Properties window, click the Security tab.
- For each Web content zone, click on the Default Level button to set each zone to the default setting.
- Click OK.
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_CRYPTLOCK.TU. 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 9
Restore encrypted files from backup.
