We have recently had this complain from our various Shared hosting as well as Dedicated Server hosting clients that MSSQL Webadmin ASP .NET Enterprise Manager is having a virus / trojan on it. When the first complain arrived we too thought that there seems to be a problem with the server and might be MSSQL Webadmin ASP .NET Enterprise Manager has got an injection in it. But after receiving too many complains from most of our dedicated server clients we started investigating the problem and now we knew that this is something that has happen globally. After viewing MSSQL Webadmin ASP .NET Enterprise Manager on Plesk server it looked as the picture below:

We understood that the problem was not with the mssql.domain_name link but the virus alert only happened after click on ASP .NET Enterprise Manager, Recomended this site. And the link was:

www.referralplanet.com/referral/windows/referralWindow.asp?id=17

Since the site was not hosted with us we had a sigh of relief that the problem is not with the server however we thought we still have a security problem if the link has been injected into ASP .NET Manager site in IIS, may be due to a security issue with Plesk control panel. And after checking several servers we came to know that the problem has happened to the site that is recommended on MSSQL Webadmin site and not the server.

If you want to remove this link from your server as well as from the MSSQL WebAdmin site then follow the steps below:

1. Login into the server through RDP with Administrator user.
2. Go to D:\inetpub\vhosts\sqladmin\mssql\app
3. Open the navbar.aspx page in notepad
4. Go to line number 119 and remove the code below:

<!-- Begin ReferralPlanet.com Referral Script -->
<a onclick="refWindow=window.open('http:// www.referralplanet.com/referral/windows/referralwindow.asp?id=18','referralWindow' ,'width=350,height=520,scrollbars=yes,menubar=no,resizable=yes'); refWindow.focus(); return false;" target=_blank href="http:// www.referralplanet.com/referral/windows/referralWindow.asp?id=17">
<IMG alt="Click Here To Tell A Friend" src="images/tellafriend.gif" border=0></A>
<!-- Begin ReferralPlanet.com Referral Script -->

5. Save the file and exit.

This problem must have infected millions of computer in the world. Let see when chinese hacker stop putting their shit on other’s website and get mature.

The architecture of Microsoft MSSQL Server is mainly divided into three components:

1. SQLOS: which implements the basic services required by MS SQL Server, including thread scheduling, I/O stat management and memory management.

2. Relational Engine: which implements the relational database components including support for databases, tables, queries and stored procedures as well as implementing the type system.

3. Protocol Layer: which exposes the MS SQL Server functionality.

SQLOS

SQLOS is the base component in the Windows SQL Server architecture. It implements functions normally associated with the Operating System, thread scheduling, memory management, I/O management, buffer pool management, resource management, synchronization primitives and locking, and deadlock detection. Because the requirements of Windows SQL Server are highly specialized, it implements its own memory and thread management system, rather than using the generic one implemented in the OS. SQLOS also includes synchronization primitives for locking as well as monitoring for the worker threads to detect and recover from deadlocks.

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The clustered nodes use a “heartbeat” signal to check whether each node is alive, at both the operating system level and the SQL Server level. At the operating system level, the nodes in the cluster are in constant communication, validating the health of all the nodes.

After installing a SQL Server failover cluster, the node hosting the SQL Server resource uses the Service Control Manager to check every 5 seconds whether the SQL Server service appears to be running. This “LooksAlive” check does not impact the performance of the system, but also does not do a thorough check; the check will succeed if the service appears to be running even though it might not be operational. Because the LooksAlive check does not do a thorough check, a deeper check must be done periodically; this “IsAlive” check runs every 60 seconds.

The IsAlive check runs a SELECT @@SERVERNAME Transact-SQL query against SQL Server to determine whether the server can respond to requests. Although a reply to the IsAlive query confirms that the SQL Server service is available for requests, it does not guarantee that all user databases are available, or that the user databases are operating within necessary performance/response-time requirements.

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MS SQL 2005 Server was released after 5 servers of it previous SQL version, MS SQL 2000, Hence it required allot to revisions to cope up with the current windows development environment. Therefore MS SQL 2005 SP2 had major changes in it, with too many performances and security fixes. Microsoft could not add few revisions due to its basic development structure however they had all the scope to introduce them in SQL 2008 release. And indeed, MS SQL 2008 has many installation as well as performance fixes being applied to it and allowing Windows Administrators to have full control on SQL activities. The biggest advantage of SQL 2008 over SQL 2005 is the ability to manage and maintain server performance. SQL 2008 does not require too much resource which is the best deal for today’s Shared Hosting environment. Also an upper hand to whose to do not want to invest too much on hardware of their dedicated servers just to run SQL server on it.

I have tried to gather the major improvement introduced by Microsoft on SQL 2008 from Internet which is an advantage over SQL 2005 however it all depends on what features are useful to you in the development of your ASP .NET applications. But switching to Microsoft SQL 2008 is definitely going to improve the performance even if you don’t use any of the below feature. And not to forget that with the release of SQL 2008, Microsoft will announce “End Of Life” for SQL 2000 version, which will mean that there won’t be any official support or update release for SQL 2000.

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Ways to secure your MS SQL connection string in ASP .NET.

We have seen allot of people looking to have the best option to secure the connection string in their ASP .NET code to connect the MS SQL database since it contains the username and password of their database. It is very important to use a secure method for corporate clients and those who save Credit Card details in their MS SQL database. Or they will easily get hacked and all the important data will be exploited by the hacker. And also for those who store important data in MSSQL.

Here are the list of methods that can be used to secure your MS SQL connection string in your ASP.NET application.

METHODS:

1. Using a DSN connection string:

If you have the administrator users access to your Windows Server or use a control panel like Plesk then you can create a DSN with ODBC connector that stores the password of your database along with its name.

You will have to go to Start >> Administrative Tools >> Data Sources (ODBC) on your Windows Server with an account that has administrative privileges.

Or if you use a hosting control panel like Plesk that you can create the DSN from the control panel itself.

Once you have created the DNS you will have to mention it in your code as:

oConn.Open "DSN=mySystemDSN"

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Some times we see the error below in the event logs:

“SQL Server has encountered 1 occurrence(s) of I/O requests taking longer than 15 seconds to complete on file [T:\MSSQL\DATA\%file_name%] in database [%DB_name%] (2).  The OS file handle is 0×00000838.  The offset of the latest long I/O is: 0×000000ebdc0000“

Do you refer it to as a stalled IO? We always hear a questions such as, what’s wrong with SQL Server..? Why is SQL taking so long to read or write to the disk..? Let us discuss why it is not a MS SQL Server problem:

MS SQL Server does data file reads and writes almost exclusively as asynchronous IO, using the win32 APIs ReadFile, WriteFile, ReadFileScatter and WriteFileGather. Each of these APIs behave in a fairly similar steps, the caller sends in a handle to the file, some memory location to read or write, the size of the block and a structure that tells the kernel how to handle the IO. In MS SQL Server’s case, how to handle the IO is Asynchronously, please.  The call returns immediately so that the thread issuing so that the IO can get out of the way and make life happy for other users who are also waiting got their query to return.

The catch here is that, ordinarily the time between the Asynchronous call to read or write and the completion of the read or write should be on the order of 10ms. The longer it takes for an IO to return the more noticeable a performance impact there is to end users.

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