TROJ_CRYPTIC.BN
Windows 2000, Windows XP, Windows Server 2003
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
319,488 bytes
EXE
Yes
21 Jul 2010
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 drops the following files:
- %System%\javastat.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It drops the following copies of itself into the affected system:
- %Application Data%\{Random Folder}\{Random File Name}.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
It creates the following folders:
- %Application Data%\{Random Folder}\{Random Folder}
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
{Malware File Name} = "%Application Data%\{Random Folder}\{Random File Name}.exe"
Other System Modifications
This Trojan adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\Session Manager\AppCertDlls
autoping = "%System%\javastat.dll"
It adds the following registry keys as part of its installation routine:
HKEY_CURRENT_USER\Software\AppDataLow\
{956d7e53-6f96-61fd-3738-5bec812a45fe}
NOTES:
It uses its file name as the folder name of its created folder.
SOLUTION
8.900
7.328.02
21 Jul 2010
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Terminate a process file/s detected as TROJ_CRYPTIC.BN
*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.
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\Microsoft\Windows\CurrentVersion\RunOnce
- {Malware File Name} = "%Application Data%\{Random Folder}\{Random File Name}.exe"
- {Malware File Name} = "%Application Data%\{Random Folder}\{Random File Name}.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\AppCertDlls
- autoping = "%System%\javastat.dll"
- autoping = "%System%\javastat.dll"
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_CURRENT_USER\Software\AppDataLow
- {956d7e53-6f96-61fd-3738-5bec812a45fe}
- {956d7e53-6f96-61fd-3738-5bec812a45fe}
Step 5
Search and delete this file
Step 6
Search and delete these folders
Step 7
Scan your computer with your Trend Micro product to delete files detected as TROJ_CRYPTIC.BN. 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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