There will never be any shortage of stuff to write about, if you are writing about computers and viruses. Thank goodness for that. Here is another virus on the rampage -- 'cholera' is the name.

This virus was identified by Computer Associates International Inc., the fourth-largest US software producer. Cholera belongs to the new breed of viruses that operate over networks, the Internet and e-mail systems.It affects e-mail systems and goes on to block computer users from opening files. Strangely, there have been no reported cases of its infection so far.

Computer Associates says the virus is designed to attack e-mail networks by sending messages to all the e-mail addresses in an infected computer's hard drive and to prevent users from opening files stored in infected directories. The Cholera virus infects computers via e-mail with no text, but just an emoticon which looks like this: ":)". It infects and spreads when the attachment to the e-mail is opened.

Network Associates (of McAfee fame) has also reported that they are yet to get any customer complaint about this although they have been given a sample of the virus. Sal Viveros, group marketing manager at Network Associates, says, "It's considered a zoo virus. We haven't seen it in the wild at all."

The virus is similar to two viruses that infected computers worldwide this year, causing hundreds of millions of dollars in damages from lost files and lost productivity (see related story ""). The Worm.ExploreZip virus spreads via e-mail and, when opened, deletes files on company and individual computers.

A second virus, known as Melissa, also spread through e-mail, automatically sending itself to every address in an e-mail user's address book. It clogged e-mails and causing an estimated $393 million in lost productivity, according to computer security firm ICSA Inc.

Melissa's creator, a New Jersey-based computer programmer, David L. Smith, was arrested and charged with crimes that together carry maximum penalties of 40 years in prison and $48,000 in fines. Anti-virus companies too came out with the fixes promptly, but by then the damage was already done.