Google on Friday released an automated Web security scanning program called skipfish to help reduce online security vulnerabilities.

Though skipfish performs the same functions as other open-source scanning tools like Nikto and Nessus, Google engineer Michal Zalewski argues that skipfish has a several advantages.

It operates at high speed, thanks to optimized HTTP handling and a low CPU footprint, and can easily reach 2000 requests per second, he explains in a blog post.

It's easy to use, he claims.

And, he says, it incorporates advanced security logic, which helps reduce the likelihood of generating false positives. The techniques used in skipfish are similar to those used in another security tool that Google released in 2008 called ratproxy.

"As with ratproxy, we feel that skipfish will be a valuable contribution to the information security community, making security assessments significantly more accessible and easier to execute," he says.

However, in the skipfish documentation, Zalewski notes that the software is not a silver bullet for security problems and may not be right for certain purposes. "For example, it does not satisfy most of the requirements outlined in WASC Web Application Security Scanner Evaluation Criteria," he writes. "And unlike most other projects of this type, it does not come with an extensive database of known vulnerabilities for banner-type checks."

The need for security scanning tools is clear. In its Q3-Q4 2009 Trends Report, security vendor Cenzic found that 90% of Web applications have vulnerabilities.

As it happens, Cenzic offers a commercial vulnerability scanning service, starting at $399 a year, which includes nine Web attacks.

That's in addition to the attacks coming from cybercriminals, which are initially free but can incur significant costs after the fact.