If you are reading this in print, as opposed to online, you can be fairly sure that nobody is looking over your shoulder, surreptitiously monitoring which stories you are reading or which pictures you are viewing. If, however, you are reading this on the web, there is a good chance that someone, somewhere, might know exactly what you are looking at, your favourite sites, even how much money you spend online.

Spyware (or adware, as some of its proponents euphemistically call it) is software that resides and hides on computers, often reporting back to advertising companies or otherdata-capture firms that build up a profile of your habits. The technique is not new, but it is getting worse, with unsolicited surveillance now hijacking elements of your internet browser, adding toolbars or inserting rogue websites into favourites lists.

In some instances, you’ll even find that your home page has been altered, and that no matter how many times you change it back, the cuckoo site reappears. This is akin to someone breaking into your house, rearranging furniture, installing a hidden video camera and stealing a key, to give them easy access the next time they want to browse your CD collection.

“Forget Big Brother, forget surveillance cameras — now your every action online could be being recorded without your explicit permission,” warns the pressure group Spyware Watch. “This practice must be brought out into the open so that you have a choice before giving out highly personal information.”

The scourge originated — not surprisingly, perhaps — with advertising companies trying to help websites make a profit through improved customer information. It has grown into a mutant industry that could harvest private details.

The situation is exacerbated by an ever-increasing number of surveillance sources. “The problem is that spyware and adware originally came in software that told you it needed to install spyware to function properly, so you knew where it came from and you knew it was there,” says Yaman Akdeniz, director of Cyber-Rights & Cyber-Liberties. “Now, with the security problems in Internet Explorer and Outlook, the software can come from anywhere — an e-mail or a web page. There is no transparency, so you don’t even know you have it.

I’m cautious, yet I was amazed to find out how much spyware was on my machine.”

Analysis from the leading American internet service provider Earthlink suggests that upwards of one in five computers may be corrupted by spyware. Head to www.earthlink.net/spyaudit to run a test on your machine and you may be surprised by how much snooping is going on inside your computer.

What is worrying security officials is the blurring between spyware and illegal trojan-horse computer code that acts as a back door to your machine. Once inside, a trojan enables hackers to access your system or log keystrokes to show what you are typing — be it chat-room chittering or bank passwords. Nobody would suggest that all snooping software is actively monitoring such private traffic, but the capability exists.

Although UK law offers some protection under the Computer Misuse Act and Data Protection Act, with most of the insidious software originating overseas, there is little victims can do. The onus therefore falls — as with virus protection — on the end user, and this is an area complicated by immature software companies. Not all are reputable. American investigators are, for example, studying claims that Spy Wiper has been hijacking browsers to scare surfers into buying protection.

Security companies are slowly integrating spyware protection into their software, but spy-slayers should also try the free Spybot: Search and Destroy and Ad-Aware 6.0 programs. Be warned: some spyware buries itself in your all-important registry files, so back up your system before taking up your licence to kill.

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