Somewhere out on the Internet, an Electric Bong may be in danger. The threat: a well-crafted Google query that could allow a hacker to use Google's massive database as a resource for intrusion.

"Electric Bong" was one of a number of household devices that security researcher Johnny Long came across when he found an unprotected Web interface to someone's household electrical network. To the right of each item were two control buttons, one labelled "on," the other, "off."

Long, a researcher with Computer Sciences and author of the book, "Google Hacking for Penetration Testers," was able to find the Electric Bong simply because Google contains a lot of information that wasn't intended to lie unexposed on the Web. The problem, he said at the Black Hat USA conference in Las Vegas last week, lies not with Google itself but with the fact that users often do not realise what Google's powerful search engine has been able to dig up.

In addition to power systems, Long and other researchers were able to find unsecured Web interfaces that gave them control over a wide variety of devices, including printer networks, PBX (private branch exchange) enterprise phone systems, routers, Web cameras, and of course Web sites themselves. All can be uncovered using Google, Long said.

But the effectiveness of Google as a hacking tool does not end there. It can also be used as a kind of proxy service for hackers, Long said.

Although security software can identify when an attacker is performing reconnaissance work on a company's network, attackers can find network topology information on Google instead of snooping for it on the network they're studying, he said. This makes it harder for the network's administrators to block the attacker. "The target does not see us crawling their sites and getting information," he said.

Often, this kind of information comes in the form of apparently nonsensical information -- something that Long calls "Google Turds." For example, because there is no such thing as a Web site with the URL (Uniform Resource Locator) "nasa," a Google search for the query "site:nasa" should turn up zero results. instead, it turns up what appears to be a list of servers, offering an insight into the structure of Nasa's (the U.S. National Aeronautics and Space Administration's) internal network, Long said.

Combining well-structured Google queries with text processing tools can yield things like SQL (Structured Query Language) passwords and even SQL error information. This could then be used to structure what is known as a SQL injection attack, which can be used to run unauthorized commands on a SQL database. "This is where it becomes Google hacking," he said. "You can do a SQL injection, or you can do a Google query and find the same thing."

Although Google traditionally has not concerned itself with the security implications of its massive data store, the fact that it has been an unwitting participant in some worm attacks has the search engine now rejecting some queries for security reasons, Long said. "Recently, they've stepped into the game."