ASP.NET Programming Websites

Hacker Attacks and Invalid character in a Base-64 string

Jan 13, 2010 by Paul White

On my websites I have them setup to email me anytime a server error happens.  If you ever get an error like "Invalid character in a Base-64 string",  This is likely a hacker attack.   In my case it was on the members login on my client's website.  I logged in and shut down the site.  10 minutes later I started it back up and the hacker had left.  Interesting is what the HTTP RAW data reveled.

HTTP_X_FORWARDED_FOR:84.0.182.175, 84.0.162.91, 84.0.237.176, 84.0.228.6, 84.0.220.100, 84.0.147.233, 84.0.159.1, 84.0.84.37 HTTP_PROXY_CLIENT_IP:84.0.182.175, 84.0.162.91, 84.0.237.176, 84.0.228.6, 84.0.220.100, 84.0.147.233, 84.0.159.1, 84.0.84.37 HTTP_CLIENT_IP:84.0.182.175, 84.0.162.91, 84.0.237.176, 84.0.228.6, 84.0.220.100, 84.0.147.233, 84.0.159.1, 84.0.84.37

Never seen these values before.  According to the logs the IPs were from hundreds of compromised systems. However they all had these values in common.   I am going to add a rule to detect the Class A IP in the 80.x.x.x block in the HTTP_X_FORWARDED_FOR, and block.  Hopefully this helps some other people out

w3wp.exe using too much memory and resources

Oct 1, 2009 by Paul White

If you are having problems with the w3wp.exe process using too much memory, I have the solution to your problems.  Not only will this reduce the size of your w3wp.exe but it will also speed up your website and reduce the amount of transfer your site uses. 

fixing The remote host closed the connection. The error code is 0x80070057

Sep 11, 2009 by Paul White

If you are running Windows Server 2008, and IIS 7.  Then the chances are you might have seen this mystery error. The remote host closed the connection. The error code is 0x80070057.  After reading multiple forums, I have found the solution.

So if your event viewer is full of errors like this

Base:
System.Web.HttpException: The remote host closed the connection. The error code is 0x80070057. at System.Web.Hosting.IIS7WorkerRequest.RaiseCommunicationError(Int32 result, Boolean throwOnDisconnect) at System.Web.Hosting.IIS7WorkerRequest.ExplicitFlush() at System.Web.HttpResponse.Flush(Boolean finalFlush) at System.Web.HttpResponse.Flush() at System.Web.HttpWriter.Write(String s) at System.Web.UI.HtmlTextWriter.Write(String s) at ASP.photo_aspx.__Render__control1(HtmlTextWriter __w, Control parameterContainer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) at System.Web.UI.Page.Render(HtmlTextWriter writer) at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

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How to get godaddy to work with custom 404 on multiple asp.net websites

Jul 27, 2009 by Paul White

If you have found this blog post, the chances are you have already searched the web for hours trying to figure this out.  Running a single website on godaddy is not a problem.  but once you start running multiple asp.net websites on your godaddy hosting account, and they all use custom 404 handling as part of URL rewriting you will run into problems. Here is how I made it work.

Adobe ditches ASP.NET Support in Dreamweaver CS4

Dec 20, 2008 by Paul White

I first started making websites using frontpage, then I started using dreamweaver, and life was good.  This was back in the days when dreamweaver was run by macromedia.  Back when Dreamweaver was in version 4.0 ( way back ).  Well on the latest release of CS4 I guess Adobe decided that it was better to not provide any support for .NET guys like myself than to provide support for older ASP.NET 1.1 components.  I recently updated to CS4 only to discover this after the fact.  To say the lease it was not a good day.

What are good email characters?

Dec 17, 2008 by Paul White

If you search for this on google you will find long drawn out explanations of how to validate email addresses.  How about just an answer?  I have the answer, or at least my definition of an answer.

MySQL Got an error reading communication packets

Dec 10, 2008 by Paul White

Aborted Connection to db. If you have ever had this little error in MySql and asp.net, you have most likely spent countless hours googling for an answer.  I have your answer read more the solution.

SQL injection IP blacklist from the botnet

Aug 26, 2008 by Paul White

The BotNet seems to be growing faster than ever.  I have included a list of all the IPs, I have caught attempting SQL injection via querystring.  If you have your own blacklist, feel free to add these to your list.

protecting against SQL injection attacks using querystring

Aug 15, 2008 by Paul White

If you run a website that is based on SQL, or MySQL. This is a must read.  Some of my websites recently have been under attack by bots that are trying a new method of SQL injection attack. 

Using Caching to make your ASP.NET website more scalable

Jul 3, 2008 by Paul White

If you make dozens of SQL queries within a single webpage this is not the most scalable way to build a website.  ASP.NET supports Caching, allowing you to store information directly in the server's memory.  Here I give you a little information on caching and how to use it to make your websites load faster.