Announcing the findings at RSA, the NCSA said, "This is quite alarming considering botnets are comprised mostly of consumers' computers and are increasingly being used to perpetrate identity theft and spread viruses."
NCSA executive director Ron Teixeira said, last June the FBI identified more than one million infected computers that could have been used as a botnet to attack other computers, spread malware, or attack critical national infrastructure.
"Botnets continue to be an increasing threat to consumers and homeland security," he said. "Consumers' unsecured computers play a major role in helping cybercriminals conduct cybercrimes not only on the victim's computer, but also against others connected to the internet."
The study showed most respondents think it unlikely their computer could affect national security. Only 51% think it is possible for a hacker to use their computer to launch cyber attacks.
"It is alarming that consumers do not know how to secure their computers," said Teixeira. "Consumers (must) understand that safe cyber security practices not only protect them from identity theft, but also prevent cyber crime and attacks."
Other findings include:
• 51% have not changed their password in the past year
• 48% do not know how to protect themselves from cyber criminals
• 46% of consumers are not sure of what to do if they became a victim of a cyber crime.