Only 8% of UK consumers feel perfectly safe using their computer at home, according to research commissioned by analyst Point Topic.
The research questioned 5,800 adults about IT security in the wake of recent headlines about data theft and covert online monitoring.
But Point Topic discovered people were taking fewer online security precautions than six months before.
John Bosnell, an analyst at Point Topic, said, "We found 78% of consumers have some form of anti-virus software and 53% have a firewall, but this is actually a drop over the last six months.
"Our previous survey showed 85% and 56% of users saying they had adopted these respective precautions."