Inexpensive crimeware toolkits for sale in the cybercrime underground are multiplying the ranks of hackers breaking into computers around the world, according to security researchers.

Sales of these toolkits -- software packages of malicious code -- jumped in August, according to researchers from Finjan, a security company. The company reported 10 different types of crimeware toolkits being sold last month alone. The list includes includes the known MPack, NeoSploit, IcePack, WebAttacker, WebAttacker2, and MultiExploit toolkits, as well as new toolkits like random.js, vipcrypt, makemelaugh, and dycrypt.

"Crimeware toolkits have been becoming very popular these days," said Yuval Ben-Itvhak, Finjan's chief technical officer, in an interview. "Anyone can buy this for a few hundred dollars to infect users and collect data -- passwords, personal data, user names -- and use it or sell it. Today, to be a cybercriminal, you don't need to be an expert."

Ben-Itvhak said malware authors create the toolkits and then sell them to would-be hackers for anywhere from $100 to $500. And these aren't unsophisticated scripts. The toolkits are set up to be automatically updated whenever new exploits become available. They're also updated as new anti-forensic techniques come out, allowing them to evade detection by traditional signature, reputation and URL-based security products.

The toolkits often are even designed to spit out reports so the hacker can track how many users he's infected, what kind of browsers they're using, where they're located, and what Trojan was installed on their machine.

Some of the packages are even open-source, with various malware authors contributing to them. Ben-Itvhak said these toolkits tend to have fewer bells and whistles, while the commercial toolkits will cost some money but have more features.

These tools let just a few hackers cause problems for a lot of users. Ben-Itvhak said Finjan's researchers tracked control servers, got a look at some hackers' toolkit reports, and estimate that just 58 hackers had infected half a million users.

"There are so many more criminals using these tools," he said, noting that six months ago there might have been few hundred and today there are thousands taking advantage of the toolkits. "The toolkits are boosting numbers to a level that's just out of control."