As the "MyDoom" virus sweeps through millions of computers, this is a good time to think about protecting your financial data.

The latest virus installs a program that can let hackers take control of your computer, meaning they could record whatever you type in on your keyboard and steal your passwords, credit-card details and more.

But financial transactions online aren't necessarily less secure than the offline version that leaves a paper trail. Here are a few precautionary steps:

Look for the padlock. Before entering any information in a financial site such as your bank, check for a small padlock symbol at the bottom of the browser border and see if the Web address starts with https instead of the usual http. Both indicate you have a secure connection.

Don't open it. Most viruses are transmitted by e-mail attachments. Never open attachments you don't recognize or have not specifically requested, even if the e-mail is from a friend -- they may unwittingly be sending you a virus. Especially watch out for program files, or any file in a format you don't recognize.

Stay up to date. With perhaps a dozen new viruses every day, make sure you update your virus-protection software regularly. Most providers let you set up your computer to download updates automatically at regular intervals, and many packages also come with a firewall that provides additional security.

Change your password. You should change your password about once a month, and make it something difficult to guess -- adding numbers or symbols helps to thwart hackers. Also never give out your password -- banks and tech-support people generally never ask for it, but scammers do.