Internet criminals might be rethinking a favourite scam for stealing people's personal information.

A report being released Wednesday by IBM Corp. shows a big drop in the volume of "phishing" emails, in which fraud artists send what looks like a legitimate message from a bank or some other company. If the recipients click on a link in phishing email, they land on a rogue website that captures their passwords, account numbers or any other information they might enter.

IBM's midyear security report found that phishing accounted for just 0.1 per cent of all spam in the first six months of this year. In the same period in 2008, phishing made up 0.2 per cent to 0.8 per cent of all spam.

It's not clear what, if anything, the decline means. (It also doesn't appear to be a statistical illusion caused by an increase in other kinds of spam. IBM said overall spam volume hasn't expanded, like it did in years past.)

"That is a huge, precipitous decline in the amount of phishing," said Kris Lamb, director of the X-Force research team in IBM's Internet Security Systems division, which did the report. But "I wouldn't tell anybody that phishing has died as a threat."

Users get better at spotting fake sites

Lamb believes phishing might have fallen off because computer users are getting smarter about identifying phony web sites. Security software is also getting better at filtering out phishing sites before web surfers ever seen them.

It could also be that criminals are moving on from phishing to another kind of attack, involving malicious software. IBM said it is seeing more instances of "Trojan horse" programs, which are used to spy on victims.

Dean Turner, director of Symantec Corp.'s global intelligence network, who was not involved in IBM's research, said Symantec has also noticed less phishing, but warned that it could increase again later in the year. Phishing scams spike around the holidays, he said.

IBM found that criminals are changing the types of businesses they attack with phishing. Sixty-six percent of phishing targets were banks, down from 90 per cent last year. Meanwhile, companies that handle online payments, like PayPal, are being mimicked in phishing messages more frequently.

To protect yourself against phishing, access sensitive sites on your own, rather than by following links in emails, which might lead to phishing sites.