Symantec incorrectly flags Yahoo Mail as a virus

Starting sometime on Tuesday, accessing the beta version of Yahoo Mail on a PC with Symantec's updated antivirus software caused alarm bells to go off. The security software reported finding the "Feebs" worm on the Yahoo Web pages.

That warning was in error, Symantec said Wednesday.

"Symantec antivirus products...triggered a false-positive alert with Yahoo Mail beta," Vincent Weafer, a senior director at Symantec Security Response, said in an e-mailed statement.

Symantec started receiving reports of the incorrect warnings Tuesday evening, after it had sent out the latest antivirus definitions for its products. Symantec issued updated definitions later in the evening to fix the mistake, Weafer said.

"Given the timeliness of the response and the limited number of products which would have used those (incorrect) definitions, we expect the impact of this to be very limited," Weafer said, adding that Symantec received about a dozen reports from people who saw the false warning.

While Symantec downplayed the issue, the SANS Internet Storm Center reported that multiple people have seen the Symantec warning appear on their PC. One CNET News.com reader in an alarmed e-mail wrote that Yahoo Mail appeared to be hacked.

Such errors happen occasionally with security software. For example, Microsoft's Windows Live OneCare in November warned that Google's Gmail contained a virus. Earlier last year, McAfee's security tools flagged Excel and other legitimate applications as viruses, and Symantec last summer identified a Church of England software program as spyware.

Typically, these errors can be fixed by updating the signature files in security applications. These signatures are the rules used by the security program to identify malicious software.