Spyware is computer software that is installed surreptitiously on a personal computer to intercept or take partial control over the user's interaction with the computer, without the user's informed consent.
While the term spyware suggests software that secretly monitors the user's behavior, the functions of spyware extend well beyond simple monitoring. Spyware programs can collect various types of personal information, such as Internet surfing habit, sites that have been visited, but can also interfere with user control of the computer in other ways, such as installing additional software, redirecting Web browser activity, accessing websites blindly that will cause more harmful viruses, or diverting advertising revenue to a third party. Spyware can even change computer settings, resulting in slow connection speeds, different home pages, and loss of Internet or other programs. In an attempt to increase the understanding of spyware, a more formal classification of its included software types is captured under the term privacy-invasive software.
In response to the emergence of spyware, a small industry has sprung up dealing in anti-spyware software. Running anti-spyware software has become a widely recognized element of computer security best practices for Microsoft Windows desktop computers. A number of jurisdictions have passed anti-spyware laws, which usually target any software that is surreptitiously installed to control a user's computer
-=Anti-spyware programs=-
Lavasoft's Ad-Aware 2008Many programmers and some commercial firms have released products designed to remove or block spyware. Steve Gibson's OptOut pioneered a growing category. Programs such as Lavasoft's Ad-Aware SE (free scans for non-commercial users, must pay for other features) and Patrick Kolla's Spybot - Search & Destroy (all features free for non-commercial use) rapidly gained popularity as effective tools to remove, and in some cases intercept, spyware programs. More recently Microsoft acquired the GIANT AntiSpyware software, rebranding it as Windows AntiSpyware beta and releasing it as a free download for Genuine Windows XP and Windows 2003 users. In 2006, Microsoft renamed the beta software to Windows Defender (free), and it was released as a free download in October 2006 and is included as standard with Windows Vista. Other well-known commercial anti-spyware products include:
PC Tools's Spyware Doctor (free scans but you have to pay to remove the spyware)
Sunbelt Software's Counterspy (15-day free trial)
Trend Micro's HijackThis (free)
Webroot Software's Spy Sweeper (free version does not remove spyware)
ParetoLogic's Anti-Spyware and XoftSpy SE (free version does not remove spyware)
Major anti-virus firms such as Symantec, McAfee and Sophos have come later to the table, adding anti-spyware features to their existing anti-virus products. Early on, anti-virus firms expressed reluctance to add anti-spyware functions, citing lawsuits brought by spyware authors against the authors of web sites and programs which described their products as "spyware". However, recent versions of these major firms' home and business anti-virus products do include anti-spyware functions, albeit treated differently from viruses. Symantec Anti-Virus, for instance, categorizes spyware programs as "extended threats" and now offers real-time protection from them (as it does for viruses).
Recently, the anti-virus company Grisoft, creator of AVG Anti-Virus, acquired anti-spyware firm Ewido Networks, re-labeling their Ewido anti-spyware program as AVG Anti-Spyware Professional Edition. AVG also used this product to add an integrated anti-spyware solution to some versions of the AVG Anti-Virus family of products, plus made a freeware AVG Anti-Spyware Free Edition available for private and non-commercial use. This shows a trend by anti virus companies to launch a dedicated solution to spyware and malware. Zone Labs, creator of Zone Alarm firewall have also released an anti-spyware program.
-=Fake anti-spyware programs=-
See also: List of fake anti-spyware programs
See also: Rogue software
Malicious programmers have released a large number of fake anti-spyware programs, and widely distributed Web banner ads now spuriously warn users that their computers have been infected with spyware, directing them to purchase programs which do not actually remove spyware—or worse, may add more spyware of their own.[44][45]
The recent proliferation of fake or spoofed antivirus products has occasioned some concern. Such products often bill themselves as antispyware, antivirus, or registry cleaners, and sometimes feature popups prompting users to install them. This software is called rogue software.
It recommended that users do not install any freeware claiming to be anti-spyware unless it is verified to be legitimate. Some known offenders include:
AntiVirus Gold
ContraVirus
Errorsafe (AKA system doctor)
MacSweeper
PAL Spyware Remover
Pest Trap
PSGuard
SpywareStrike
Spyware Quake
Spydawn
Spylocked
SpyShredder
Spy Sheriff
Spy Wiper
UltimateCleaner
WinAntiVirus Pro 2006
WinFixer
WorldAntiSpy