An e-mail referencing a vaccine for swine flu is circulating that includes a link to a malicious file on a Mexican Web site that is designed to steal bank log-in information, security firm SonicWall said. The e-mail, which is in Spanish, has a link to the Qhost.NJI Trojan on a Web site that appears to be legitimate but has probably been hacked, said Nick Bilogorskiy, manager of antivirus research at SonicWall.