If you’re a CEO and you read this, you may be tempted to ban your traveling workers from using iPhones, iPads , laptops and any other mobile devices. Symantec says its research shows that about 35 percent of workers are more likely to expose the company to malware while they’re on the road than in the office.

The MessageLabs Intelligence report says that companies have to create usage policies that deter employees from visiting web sites that may be harmful, offensive or illegal while they’re on the road. Roaming workers are 5.4 times more likely to trigger a block — where corporate security software blocks the site from loading — than office workers. Traveling workers are far more likely to browse shopping, search engines, personals and dating sites on the road. (Meanwhile, office workers are more likely to access adult or sexually explicit sites.)

In general, this finding means that workers follow the rules when they’re in the office and someone might be watching them, but are more likely to behave badly when they’re out of the office, said Paul Wood, MessageLabs senior analyst. It’s one more reason that there is a lot more investment going into mobile security these days.

In other news, Symantec said that spam now accounts for 91.9 percent of all email, down in September by 0.3 percentage points compared to August. In September, viruses were carried by one in 218.7 emails, up 0.15 percent from August. Hungary won the award of the most spammed country, with spam as a percentage of total email is at 96 percent.