The idea is that by using familiar words and phrases, such as passwords, a pet's name, or a company name, users will be more likely to open the e-mail. Anti-spam software firm MessageLabs said it discovered the use of this new technique last week.
Matt Sergeant, the firm's Senior Anti-Spam Technologist, said:
"If you receive an e-mail with your son or daughters name in the subject line, for example, you're unlikely to delete it. This represents a shift on behalf of some spammers from a random, scattergun approach to a more tailored attack."
Sergeant said it does not yet appear to be a widespread technique, but warned computer users to be on their guard.