Mass SQL injectionApril 24, 2008 – 5:18 AM
There’s another round of mass SQL injections going on which has infected hundreds of thousands of websites.
Performing a Google search results in over 510,000 modified pages.
As more and more websites are using database back-ends to make them faster and more dynamic, it also means that it’s crucial to verify what information gets stored in or requested from those databases — especially if you allow users to upload content themselves which happens all the time in discussion forums, blogs, feedback forms, et cetera.
Unless that data is sanitized before it gets saved you can’t control what the website will show to the users. This is what SQL injection is all about, exploiting weaknesses in these controls. In this case the injection code starts off like this (note, this is not the complete code):
DECLARE%[email protected]%20NVARCHAR(4000);SET%[email protected]=CAST(0x440045004300
Which when decoded becomes:
DECLARE @T varchar(255)’@C varchar(255) DECLARE Table_Cursor
CURSOR FOR select a.name’b.name from sysobjects a’syscolumns b
where a.id=b.id and a.xtype=’u’ and (b.xtype=99 or b.xtype=35
So far three different domains have been used to host the malicious content — nmidahena(dot)com, aspder(dot)com and nihaorr1(dot)com. There’s a set of files that gets loaded from these sites that attempts to use different exploits to install an online gaming trojan. Right now the initial exploit page on all domains are unaccessible but that could change. So if you’re a firewall administrator we recommend you to block access to them.
So what should you do?
First of all, search your website logs for the code above and see if you’ve been hit. If so, clean up your database to prevent your website visitors from becoming infected. Second, make sure that all the data you pass to your database is sanitized and that no code elements can be stored there. Third, block access to the sites above. Fourth, make sure the software you use is patched, F-Secure Health Check is an easy way to do this. Fifth, keep your antivirus solution up-to-date.