SPYWARE is a type of malware that is installed on computers and collects little bits of information at a time about users without their knowledge. The presence of spyware is typically hidden from the user, and can be difficult to detect. Typically, spyware is secretly installed on the user's personal computer. Sometimes, however, spywares such as keyloggers are installed by the owner of a shared, corporate, or public computer on purpose in order to secretly monitor other users.
While the term spyware suggests software that secretly monitors the user's computing, the functions of spyware extend well beyond simple monitoring. Spyware programs can collect various types of personal information, such as Internet surfing habits and sites that have been visited, but can also interfere with user control of the computer in other ways, such as installing additional software and redirecting Web browser activity. Spyware is known to change computer settings, resulting in slow connection speeds, different home pages, and/or loss of Internet or functionality of other programs.
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 practices for computers, especially those running Microsoft Windows. A number of jurisdictions have passed anti-spyware laws, which usually target any software that is surreptitiously installed to control a user's computer.
HISTORY AND DEVELOPMENT
The first recorded use of the term spyware occurred on October 16, 1995 in a Usenet post that poked fun at Microsoft's business model. Spyware at first denoted software meant for espionage purposes. However, in early 2000 the founder of Zone Labs, Gregor Freund, used the term in a press release for the ZoneAlarm Personal Firewall. Since then, "spyware" has taken on its present sense. According to a 2005 study by AOL and the National Cyber-Security Alliance, 61 percent of surveyed users' computers had some form of spyware. 92 percent of surveyed users with spyware reported that they did not know of its presence, and 91 percent reported that they had not given permission for the installation of the spyware. As of 2006, spyware has become one of the preeminent security threats to computer systems running Microsoft Windows operating systems. Computers where Internet Explorer (IE) is the primary browser are particularly vulnerable to such attacks not only because IE is the most widely-used, but because its tight integration with Windows allows spyware access to crucial parts of the operating system.
The Windows Registry contains multiple sections that by modifying keys values allows software to be executed automatically when the operating system boots. Spyware can exploit this design to circumvent attempts at removal. The spyware typically will link itself from each location in the registry that allows execution. Once running, the spyware will periodically check if any of these links are removed. If so, they will be automatically restored. This ensures that the spyware will execute when the operating system is booted even if some (or most) of the registry links are removed.
Spyware does not directly spread in the manner of a computer virus or worm: generally, an infected system does not attempt to transmit the infection to other computers. Instead, spyware gets on a system through deception of the user or through exploitation of software vulnerabilities.
Most spyware is installed without users' knowledge. Since they tend not to install software if they know that it will disrupt their working environment and compromise their privacy, spyware deceives users, either by piggybacking on a piece of desirable software, or by tricking them into installing it (the Trojan horse method). Some "rogue" spyware programs masquerade as security software.
The distributor of spyware usually presents the program as a useful utility—for instance as a "Web accelerator" or as a helpful software agent. Users download and install the software without immediately suspecting that it could cause harm.
Spyware can also come bundled with other software. The user downloads a program and installs it, and the installer additionally installs the spyware. Although the desirable software itself may do no harm, the bundled spyware does. In some cases, spyware authors have paid shareware authors to bundle spyware with their software. In other cases, spyware authors have repackaged desirable freeware with installers that slipstream spyware.
Some spyware authors infect a system through security holes in the Web browser or in other software. When the user navigates to a Web page controlled by the spyware author, the page contains code which attacks the browser and forces the download and installation of spyware. The spyware author would also have some extensive knowledge of commercially-available anti-virus and firewall software. This has become known as a "drive-by download", which leaves the user a hapless bystander to the attack. Common browser exploits target security vulnerabilities in Internet Explorer and in the Sun Microsystems Java runtime.
The installation of spyware frequently involves Internet Explorer. Its popularity and history of security issues have made it the most frequent target. Its deep integration with the Windows environment and scriptability make it an obvious point of attack into Windows. Internet Explorer also serves as a point of attachment for spyware in the form of Browser Helper Objects, which modify the browser's behavior to add toolbars or to redirect traffic.
EFFECTS AND BEHAVORS
A spyware program is rarely alone on a computer: an affected machine usually has multiple infections. Users frequently notice unwanted behavior and degradation of system performance. A spyware infestation can create significant unwanted CPU activity, disk usage, and network traffic. Stability issues, such as applications freezing, failure to boot, and system-wide crashes, are also common. Spyware, which interferes with networking software commonly causes difficulty connecting to the Internet.
In some infections, the spyware is not even evident. Users assume in those situations that the issues relate to hardware, Windows installation problems, or another infection. Some owners of badly infected systems resort to contacting technical support experts, or even buying a new computer because the existing system "has become too slow". Badly infected systems may require a clean reinstallation of all their software in order to return to full functionality.
Only rarely does a single piece of software render a computer unusable. Rather, a computer is likely to have multiple infections. The cumulative effect, and the interactions between spyware components, causes the symptoms commonly reported by users: a computer, which slows to a crawl, overwhelmed by the many parasitic processes running on it. Moreover, some types of spyware disable software firewalls and anti-virus software, and/or reduce browser security settings, thus opening the system to further opportunistic infections, much like an immune deficiency disease. Some spyware disables or even removes competing spyware programs, on the grounds that more spyware-related annoyances make it even more likely that users will take action to remove the programs.
Some other types of spyware use rootkit like techniques to prevent detection, and thus removal. Targetsoft, for instance, modifies the "Winsock" Windows Sockets files. The deletion of the spyware-infected file "inetadpt.dll" will interrupt normal networking usage.
A typical Windows user has administrative privileges, mostly for convenience. Because of this, any program the user runs (intentionally or not) has unrestricted access to the system. As with other operating systems, Windows users too are able to follow the principle of least privilege and use non-administrator least user access accounts, or to reduce the privileges of specific vulnerable Internet-facing proceses such as Internet Explorer (through the use of tools such as DropMyRights). However as this is not a default configuration, few users do this.
In Windows Vista, by default, a computer administrator runs everything under limited user privileges. When a program requires administrative privileges, Vista will prompt the user with an allow/deny pop-up (see User Account Control). This improves on the design used by previous versions of Windows.
Spyware has been used to surreptitiously monitor electronic activities of partners in intimate relationships, generally to uncover evidence of infidelity. At least one software package, Loverspy, was specifically marketed for this purpose. Depending on local laws regarding communal/marital property, observing a partner's online activity without their consent may be illegal; the author of Loverspy and several users of the product were indicted in California in 2005 on charges of wiretapping and various computer crimes.
REMEDIES AND PREVENTION
As the spyware threat has worsened, a number of techniques have emerged to counteract it. These include programs designed to remove or to block spyware, as well as various user practices which reduce the chance of getting spyware on a system.
Nonetheless, spyware remains a costly problem. When a large number of pieces of spyware have infected a Windows computer, the only remedy may involve backing up user data, and fully reinstalling the operating system.
Many programmers and some commercial firms have released products dedicated to remove or block spyware.
Anti-spyware programs can combat spyware in two ways:
1. They can provide real time protection against the installation of spyware software on your computer. This type of spyware protection works the same way as that of anti-virus protection in that the anti-spyware software scans all incoming network data for spyware software and blocks any threats it comes across.
2. Anti-spyware software programs can be used solely for detection and removal of spyware software that has already been installed onto your computer. This type of spyware protection is normally much easier to use and more popular. With this spyware protection software you can schedule weekly, daily, or monthly scans of your computer to detect and remove any spyware software that has been installed on your computer. This type of anti-spyware software scans the contents of the windows registry, operating system files, and installed programs on your computer and will provide a list of any threats found, allowing you to choose what you want to delete and what you want to keep.
Such programs inspect the contents of the Windows registry, the operating system files, and installed programs, and remove files and entries which match a list of known spyware components. Real-time protection from spyware works identically to real-time anti-virus protection: the software scans disk files at download time, and blocks the activity of components known to represent spyware. In some cases, it may also intercept attempts to install start-up items or to modify browser settings. Because many spyware and adware are installed as a result of browser exploits or user error, using security software (some of which are antispyware, though many are not) to sandbox browsers can also be effective to help restrict any damage done.
Like most anti-virus software, many anti-spyware/adware tools require a frequently-updated database of threats. As new spyware programs are released, anti-spyware developers discover and evaluate them, making "signatures" or "definitions" which allow the software to detect and remove the spyware. As a result, anti-spyware software is of limited usefulness without a regular source of updates. Some vendors provide a subscription-based update service, while others provide updates free. Updates may be installed automatically on a schedule or before doing a scan, or may be done manually.
To deter spyware, computer users have found several practices useful in addition to installing anti-spyware programs.
Many system operators install a web browser other than IE, such as Opera, Google Chrome or Mozilla Firefox. Though no browser is completely safe, Internet Explorer is at a greater risk for spyware infection due to its large user base as well as vulnerabilities such as ActiveX.
Some ISPs—particularly colleges and universities—have taken a different approach to blocking spyware: they use their network firewalls and web proxies to block access to Web sites known to install spyware. On March 31, 2005, Cornell University's Information Technology department released a report detailing the behavior of one particular piece of proxy-based spyware, Marketscore, and the steps the university took to intercept it. Many other educational institutions have taken similar steps. Spyware programs which redirect network traffic cause greater technical-support problems than programs which merely display ads or monitor users' behavior, and so may more readily attract institutional attention.
Some users install a large hosts file which prevents the user's computer from connecting to known spyware-related web addresses. However, by connecting to the numeric IP address, rather than the domain name, spyware may bypass this sort of protection.
Spyware may get installed via certain shareware programs offered for download. Downloading programs only from reputable sources can provide some protection from this source of attack.
The first step to removing spyware is to put a computer on "lockdown". This can be done in various ways, such as using anti-virus software or simply disconnecting the computer from the internet. Disconnecting the internet prevents controllers of the spyware from being able to remotely control or access the computer. The second step to removing the spyware is to locate it and remove it, manually or through use of credible anti-spyware software. During and after lockdown, potentially threatening websites should be avoided.