Grand National betting warning

If you plan on placing money on a horse for this weekend's Grand National at Aintree then security experts are warning that you should be very careful.

Cybercriminals who intend to steal bank or credit card details may have placed 'keyloggers' - software that can record which keys you have pressed - on the PCs of unwitting gamblers, said security firm Webroot.

What's more, they may have managed to sneak the malware past your anti-virus software without it being detected if you haven't kept your security software up to date.

Web User's guide to keyloggers

The keylogger can then record all the keys you press when inputting your payments details into an online gambling site and send the information back to the criminals.

Nick Banks of Webroot said: "At Webroot, we're seeing a trend that shows cybercriminals are becoming more sophisticated and dedicated to challenging anti-malware vendors.

"Hackers churn out updates or new variants to get past detection at the desktop, so that they can continue to harvest personal information unchallenged," Banks continued.

Grand National: runners and riders

You are advised to ensure that your security software is fully updated and that you are also running the latest version of your browser such as Internet Explorer 8 or Firefox 3.0.8.