Ten years ago you knew you had been hacked when a large portion of your disk drive suddenly went missing. Today experts say it is not that simple, with hackers and botnet-herders employing increasingly sophisticated techniques to keep their presence on your computer a secret.
'Hackers don't want you to know they have compromised your network, and some malware programs are so sophisticated that they can crash your antivirus so that you won't be alerted to the infection,' said Gerald Hong, director of Hong Kong-based Lapcom.
So how do you know if your computer has been breached?
'There are three signs to watch out for if you suspect your computer has become a botnet zombie,' Mr Hong said. 'The first is that the computer hard disk keeps running all the time even when the machine is idle. The second is when your contacts start complaining that you keep sending them spam. And last, your machine performs slowly for no reason.'
The solution for home users was simple, Mr Hong said. 'Just install a good antivirus package with quarantine capabilities and make sure it has a self-protect function to prevent it from being shutdown in the future.'
However, if you are on a network, it becomes more serious.
