The Mimail-J virus threat continues, but antivirus experts say it has reached its peak in infections.
Mimail-J is very similar to Mimail-I, which emerged last week. Both arrive in e-mails warning recipients that their PayPal accounts would expire unless they enter some personal data. The notable difference is Mimail-J asks for additional personal information.
The reason for the change is the information captured by Mimail-I probably wasn't very useful, said Mikko Hypponen, manager of antivirus research for Finland-based F-Secure Corp. That worm only collected credit card numbers and expiration dates.
Mimail-J went one step further asking for the recipients name, address, Social Security number and mother's maiden name. Such information, in addition to the credit card details, would be much more useful to people with nefarious intentions.
"You can't buy anything online anymore with just the credit card number and expiration date," Hypponen said. "Sites do database matches with the street address and name."
The worm peaked on Tuesday, though it's likely to still be a threat for a few days, Hypponen said. Since Mimail-J first appeared Friday, UK-based e-mail filtering outsourcer MessageLabs said it has stopped more than 70,000 copies.