Antivirus software companies issued warnings and software updates on Tuesday and Wednesday for a new worm, Wallon, that uses deceptive Web links to Yahoo.com to trick users into downloading malicious programs.
Wallon first appeared last Friday and spreads in e-mail messages. However, antivirus companies reported increased instances of the worm on Tuesday and said users could be tricked by its e-mail messages, which do not contain virus-infected file attachments.
Symantec Corp. and Network Associates Inc."s (NAI"s) McAfee Antivirus Emergency Response Team said Wallon was a low-level threat. However, other companies, including Sophos PLC and F-Secure Corp., said they received numerous reports of the worm.