RANSOM_CRYDAP
Ransom:MSIL/Crydap.A (Microsoft); Trojan-Ransom.Win32.Crypren.acld (Kaspersky); Gen:Variant.Zusy.182819 (BitDefender)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: No
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.
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 creates the following folders:
- %Application Data%\PadCrypt
(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.)
Other System Modifications
This Trojan adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Tracing\package_RASAPI32
HKEY_LOCAL_MACHINE\Software\Microsoft\
Tracing\package_RASMANCS
It adds the following registry entries:
HKEY_CURRENT_USER\Software\PadCrypt\
Chat
message-{message number} = {time} (BOT): {Chat Messages}
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}.{BLOCKED}.76.75
It requires the existence of the following files to properly run:
- %Application Data%\PadCrypt\encrypted_files.dat
- %Application Data%\PadCrypt\unistl.exe
(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.)
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
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\PadCrypt\Chat
- message-{message number} = {time} (BOT): {Chat Messages}
- message-{message number} = {time} (BOT): {Chat Messages}
Step 4
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.
- HKEY_LOCAL_MACHINE\Software\Microsoft\Tracing\package_RASAPI32
- HKEY_LOCAL_MACHINE\Software\Microsoft\Tracing\package_RASMANCS
Step 5
Search and delete these folders
- %Application Data%\PadCrypt
Step 6
Search and delete the files detected as RANSOM_CRYDAP
*Note: Some component files may be 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.
To stop the malware/grayware from running when certain files are opened:
For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the File name* input box, type the name of the file that was detected earlier.
- 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 (R2):
- 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 the name of the file that was detected earlier.
- 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 7
Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYDAP. 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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