Start-up Pramana wants to be the bot-spotter for your Web site, watching to see whether actions are initiated by real people or nasty bots remotely controlled by spammers or hackers.

Pramana has a free service called BotAlert that can report suspected bot traffic on a site. It also recently launched a paid service, BotBlock, that requires embedding a small amount of code in web pages to detect and block bot-related actions, according to David Crowder, CEO of Pramana.

"Often on a website it's not clear what is bad behaviour from a bot and what is human," Crowder says. He points out that automated bot processes can do everything from generating fraudulent content and spam to scraping data to grab content.

Pramana is positioning BotBlock, which ranges from $19.99 to $299 per month depending on the level of transactions on Web sites, as an alternative to the CAPTCHA tool mechanism commonly used to fight automated and unwanted processes such as spam. BotBlock is designed to respond to bot activity by either blocking it or feeding it false data.

Pramana was founded by Merrick Furst, Sanjay Sehgal and Guru Rajan in 2007. Like another botnet-busting start-up called Damballa, Pramana has its roots in research done at the Georgia Institute of Technology. The Alpharetta, Ga., start-up, now with seven employees, has received $2.4 million in funding, much of it from angel investors.

Online marketplace MFG.com, which claims to have 125,000 companies and 200,000 individual users accessing its portal for global manufacturing deals, started using the Pramana bot-blocking service in January.

"There are a lot of automated processes in bots trying to attack the Web site," says Mitch Free, CEO at Atlanta-based MFG.com. "Sometimes, they're just trying to steal content."

By using the Pramana service, MFG.com has been able to drop use of the CAPTCHA mechanism, which some bots were finding a way around anyway, Free says. There are some legitimate automated services used within MFG.com, and the Pramana service doesn't interfere with them, he says.