Time to think about vampires and zombies. No, not the short ones going door to door. The ones in your computer: The vampires that will suck out your passwords and credit card numbers; the virus that will turn your computer into a zombie, roaming the net to infect others. Maybe that's why October is National Cybersecurity Awareness Month.

It is not hard to avoid these problems, but it helps to know the tricks -- the digital equivalents of crosses, stakes and garlic. All that and more will be found in the eBook "Computer Security at Cornell" from Cornell Information Technologies (CIT). The revised edition out this month describes the newest hazards and has expanded information on protecting mobile devices. CIT has sent a mass email announcement to the Cornell community urging everyone to download and read the book. Departments may obtain printed copies for their staff. Email digital@cornell.edu to order.

Why should you worry about computer security? You've installed Cornell's free antivirus software. You don't have proprietary university data on your computer, like employee social security numbers or student healthcare records, and you're smart enough not to keep your own credit card numbers there. Security isn't that simple any more. It's not just university data you have to protect. Your own identity is at stake.

Did you log in to Amazon to buy something while connected to the WiFi at Collegetown Bagels? That guy at the other side of the room might now have your Amazon credentials. Did you reply to that message from your bank about problems with your account -- the one that asked you to type in your account number and password? Did you visit that website that promised those famous pictures of Scarlett Johansson? Crooks don't need to invade your computer to steal your NetID and password and use them to send spam from Cornell servers. That has happened a lot lately; it costs the university big bucks for bandwidth, wastes the time of CIT workers and causes Cornell email to be rejected by other mail systems Do you use the same password for everything? They only have to steal it once. If that isn't enough to convince you, the book includes several pages of news stories -- including some from the Cornell Chronicle -- about recent security breaches and the troubles they have caused.

Randy Newman was right: It's a jungle out there.

The eBook offers simple precautions that don't require technical expertise, like unchecking Safari's "Open safe files after downloading" preference. And did you know the color of your address bar can show how safe a website is? Reading the book will make you a bit more of a technical expert, with definitions of common security terms, a primer on how Web addresses work and descriptions of the latest methods scammers are using. There is a very useful section on how to create a strong password, and why you should. Most of this applies to computer use both at work and at home, but there's a special section on security at home, with instructions on securing your home wireless network and encrypting your exchanges with Cornell services.

There are also tips on how to know when your information has been stolen. And if you do happen to be a person who deals with sensitive data, there's a review of your responsibilities and best practices.

If all else fails (because you were too busy to read the book?), there are step-by-step instructions on how to fix problems and where to go for help.