Websense has been tracking a mass SQL-Injection attack for the past few days that started with only a few ten thousand websites and has exploded to potentially over 1 million websites.  There doesn't seem to be anything particularly new about the infection mechanism (aside of the scope of its success) and the injection itself only inserts a random snippet of HTML to redirect victims to a rogue AV site that tells the user they are infected.

One of the domains implicated in this attack was registered in October and showed up on the radar in December, so it appears the preparation of this attack has taken some time and it's been perculating for awhile.  The bulk of the infections, however, have only just occurred in the last few days.  Infected sites tend to use the same URL structure including a file "ur.php".  It appears this is only affecting sites using Microsoft SQL Server 2003/2005.

Defense against your sites getting infected is the standard things we ought to be doing anyway in regards to SQL injection (i.e.use prepared statements, filter input for control characters, whitelist if possible, blocklist if not).  Webserver administrators should also be checking for sudden appearance of files in their httpdocs directory.  More on this as it develops.

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John Bambenek
bambenek at gmail /dot/ com
Bambenek Consulting