For several months I’ve been receiving emails, from a relative which (almost always) have no subject heading, contain no text in the message body and simply show a link to an undisclosed site. The first time I received one of these messages I made the mistake of clicking on the link and received a message, from my anti-virus software (Avast free edition) warning me that the link was infected and suggesting that I click no further advice which I, of course took! Subsequently my relative sent an email to everyone in her contact list informing them that her computer had been infected and stating that the PC would be cleaned. Despite the computer now having been cleaned those infected emails keep turning up like the proverbial bad penny. At first I couldn’t understand why this should be the case, however a friend has drawn my attention to an article in yesterday’s Daily Telegraph (1 July 2011) concerning a virtually indestructible botnet which has infected approximately 4.5 million computers. The infected machines become part of a “zombie” network which those controlling it can use to spread malware and commit other criminal activity. PCs are infected by a variety of methods including by inticing computer users to click on sites offering pirated software. Once clicked on the site infects the machine which becomes part of the botnet.
The above underlines the importance of making sure your computer is protected by security software. You don’t have to spend a fortune on such software. I use Avast anti-virus (free version on my desktop and AVG anti-virus (free version) on the laptop. Both products have protected my computers from infection and I’ve never felt the need to pay for anti-virus. In addition I run Zone Alarm (free version) which can prevent potentially dodgy software from being installed on your machine and stop hackers from taking control of your computer.
There are many other good products out there and I’d strongly recommend that anyone who’s machine isn’t protected gets some protection as soon as possible.
For the Telegraph’s article on botnets please visit http://www.telegraph.co.uk/technology/news/8609309/Indestructible-botnet-snares-4.5-million-computers.html