Ransom_RAPID.THHBCAH
Trojan-Ransom.Rapid (IKARUS); Ransom.Rapid.S299828 (QUICKHEAL);
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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 is capable of encrypting files in the affected system.
It drops files as ransom note.
TECHNICAL DETAILS
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:
- %Application Data%\info.exe
(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.)
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
Encrypter_074 = %Application Data%\info.exe
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
userinfo = %Application Data%\recovery.txt
Other System Modifications
This Ransomware adds the following registry keys:
HKEY_CURRENT_USER\Software
EncryptKeys =
It adds the following registry entries:
HKEY_CURRENT_USER\Software\EncryptKeys
local_enc_private_key_len = {Hex Values}
HKEY_CURRENT_USER\Software\EncryptKeys
local_enc_private_key = {Hex Values}
HKEY_CURRENT_USER\Software\EncryptKeys
local_public_key_len = {Hex Values}
HKEY_CURRENT_USER\Software\EncryptKeys
local_public_key = {Hex Values}
Other Details
This Ransomware is capable of encrypting files in the affected system.
It adds the following scheduled tasks:
- Task Name: EncrypterSt
Schedule: On Logon
Task to be run: %Application Data%\info.exe - Task Name: Encrypter
Schedule: Every minute
Task to be run: %Application Data%\info.exe
(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.)
Ransomware Routine
This Ransomware appends the following extension to the file name of the encrypted files:
- .no_more_ransom
It drops the following file(s) as ransom note:
- %Application Data%\recovery.txt;
- {Encrypted Directories}\How Recovery Files.txt
(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.)
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
Deleting Scheduled Tasks
The following {Task Name} - {Task to be run} listed should be used in the steps identified below:
Task to be run: %Application Data%\info.exe
Task to be run: %Application Data%\info.exe
For Windows 2000, Windows XP, and Windows Server 2003:
- Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
System Tools>Scheduled Tasks. - Locate each {Task Name} values listed above in the Name column.
- Right-click on the said file(s) with the aforementioned value.
- Click on Properties. In the Run field, check for the listed {Task to be run}.
- If the strings match the list above, delete the task.
For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open the Windows Task Scheduler. To do this:
• On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
• On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter. - In the left panel, click Task Scheduler Library.
- In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
- In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
- If the said string is found, delete the task.
Step 5
Delete this registry key
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
- EncryptKeys
- EncryptKeys
Step 6
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
- Encrypter_074 = %Application Data%\info.exe
- Encrypter_074 = %Application Data%\info.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- userinfo = %Application Data%\info.exe
- userinfo = %Application Data%\info.exe
Step 7
Search and delete this file
- %Application Data%\recovery.txt;
- {Encrypted Directories}\How Recovery Files.txt
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom_RAPID.THHBCAH. 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.
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