A few weeks after my previous posting of a SQL Injection Advisory link, a new SQL Injection attack came up. Here's a post describing it; it also includes other useful links:

http://www.rtraction.com/blog/devit/sql-injection-hack-using-cast.html

A search for the query string "http://1.verynx.cn/w.js" (the quotes are part of the search string) shows that there are still sites infected today.

So, SQL Injection is alive and kicking - no big surprise here. But what may come as a surprise to you, if you're not aware of it yet, is that there is a further vulnerability here: vulnerable sites are discoverable using a search engine - it happens when the SQL Injection results in some link getting inserted in web pages, as is the case in this recent attack. This means another attacker can use a search engine to get a list of vulnerable sites and hack them a second time, for a more devastating effect. This is an instance of Search Engine Hacking - Google Hacking is currently the popular term, but any search engine can be used, not just google. Note that this is not really about hacking the search engine, but about using the search engine for hacking.

Here is more in-depth information on this techique of search engine hacking:

Google Hacking for Penetration Testers
Google Hacking page on Wikipedia
Google Hacking Database

Also note that search engine hacking goes beyond SQL Injection attacks - the sources mentioned above contain more examples of searching for different vulnerabilities. If you're the administrator of a Web site, you cannot afford to ignore this technique.