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 and executes them:
- %User Temp%\svchosta.exe (Windows Vista or above)
- %Application Data%\svchosta.exe (Windows XP or below)
(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.. %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 files:
- %System Root%\Users\Public\PUBLIC (Windows Vista or above)
- %System Root%\Documents and Settings\Default User\PUBLIC (Windows XP or below)
- %System Root%\Users\Public\UNIQUE_ID_DO_NOT_REMOVE (Windows Vista or above)
- %System Root%\Documents and Settings\Default User\UNIQUE_ID_DO_NOT_REMOVE (Windows XP or below)
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It drops and executes the following files:
- %User Temp%\svchostaaexe.bat (Windows Vista or above) -> used to delete initial copy and itself
- %Application Data%\svchostaaexe.bat (Windows XP or below) -> used to delete initial copy and itself
(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.. %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.)
Autostart Technique
This Ransomware enables its automatic execution at every system startup by dropping the following copies of itself into the Windows Common Startup folder:
- %User Startup%\start.bat -> used to execute dropped copy
(Note: %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.)
Other Details
This Ransomware displays a pop-up window with the following message:
It does the following:
- It encrypts files on all drives except for the following:
It deletes the initially executed copy of itself
Ransomware Routine
This Ransomware avoids encrypting files with the following strings in their file name:
- DECRYPT_INFORMATION.html
- UNIQUE_ID_DO_NOT_REMOVE
- *exe
- *dll
- *lnk
- *ini
- *hrmlog
It avoids encrypting files with the following strings in their file path:
- Windows
- AhnLab
- Microsoft
- Chrome
- Mozilla
- $Recycle.Bin
- WINDOWS
It drops the following file(s) as ransom note:
- {Folder Containing Encrypted Files}\DECRYPT_INFORMATION.html
NOTES:
The Ransom note displays the following:
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_LOCKY.TIAOKAI
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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
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.
- %User Temp%\svchostaaexe.bat (Windows Vista or above)
- %System Root%\Users\Public\PUBLIC (Windows Vista or above)
- %System Root%\Users\Public\UNIQUE_ID_DO_NOT_REMOVE (Windows Vista or above)
- %Application Data%\svchostaaexe.bat (Windows XP or below)
- %System Root%\Documents and Settings\Default User\PUBLIC (Windows XP or below)
- %System Root%\Documents and Settings\Default User\UNIQUE_ID_DO_NOT_REMOVE (Windows XP or below)
- {Folder Containing Encrypted Files}\DECRYPT_INFORMATION.html
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
- %User Temp%\svchostaaexe.bat (Windows Vista or above)
- %System Root%\Users\Public\PUBLIC (Windows Vista or above)
- %System Root%\Users\Public\UNIQUE_ID_DO_NOT_REMOVE (Windows Vista or above)
- %Application Data%\svchostaaexe.bat (Windows XP or below)
- %System Root%\Documents and Settings\Default User\PUBLIC (Windows XP or below)
- %System Root%\Documents and Settings\Default User\UNIQUE_ID_DO_NOT_REMOVE (Windows XP or below)
- {Folder Containing Encrypted Files}\DECRYPT_INFORMATION.html
- 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:
- %User Temp%\svchostaaexe.bat (Windows Vista or above)
- %System Root%\Users\Public\PUBLIC (Windows Vista or above)
- %System Root%\Users\Public\UNIQUE_ID_DO_NOT_REMOVE (Windows Vista or above)
- %Application Data%\svchostaaexe.bat (Windows XP or below)
- %System Root%\Documents and Settings\Default User\PUBLIC (Windows XP or below)
- %System Root%\Documents and Settings\Default User\UNIQUE_ID_DO_NOT_REMOVE (Windows XP or below)
- {Folder Containing Encrypted Files}\DECRYPT_INFORMATION.html
- 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 5
Scan your computer with your Trend Micro product to delete files detected as RANSOM_LOCKY.TIAOKAI. 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 6
Restore encrypted files from backup.
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