Windows XP has been criticized by many users[who?] for its vulnerabilities due to buffer overflows and its susceptibility to malware such as viruses, trojan horses, and worms. Nicholas Petreley for The Register notes that "Windows XP was the first version of Windows to reflect a serious effort to isolate users from the system, so that users each have their own private files and limited system privileges."[1] However, users by default receive an administrator account that provides unrestricted access to the underpinnings of the system. If the administrator's account is compromised, there is no limit to the control that can be asserted over the PC. Windows XP Home Edition also lacks the ability to administer security policies and denies access to the Local Users and Groups utility.
Microsoft executives[who?] have stated that the release of security patches is often what causes the spread of exploits against those very same flaws, as crackers figure out what problems the patches fix and then launch attacks against unpatched systems. For example, in August 2003 the Blaster worm exploited a vulnerability present in every unpatched installation of Windows XP, and was capable of compromising a system even without user action. In May 2004 the Sasser worm spread by using a buffer overflow in a remote service present on every installation. Patches to prevent both of these well-known worms had already been released by Microsoft. Increasingly widespread use of Service Pack 2 and greater use of personal firewalls may also contribute to making worms like these less common.[2]
Many attacks against Windows XP systems come in the form of trojan horse e-mail attachments which contain worms. A user who opens the attachment can unknowingly infect his or her own computer, which may then e-mail the worm to more people. Notable worms of this sort that have infected Windows XP systems include Mydoom, Netsky and Bagle. To discourage users from running such programs, Service Pack 2 includes the Attachment Execution Service which records the origin of files downloaded with Internet Explorer or received as an attachment in Outlook Express. If a user tries to run a program downloaded from an untrusted security zone, Windows XP with Service Pack 2 will prompt the user with a warning.
Spyware and adware are a continuing problem on Windows XP and other versions of Windows. Spyware is also a concern for Microsoft with regard to service pack updates; Barry Goff, a group product manager at Microsoft, said some spyware could cause computers to freeze up upon installation of Service Pack 2.[3] In January 2005, Microsoft released a free beta version of Windows Defender which removes some spyware and adware from computers.
Windows XP offers some useful security benefits, such as Windows Update, which can be set to install security patches automatically, and a built-in firewall. If a user doesn't install the updates for a long time after the Windows Update icon is displayed in the toolbar, Windows will automatically install them and restart the computer on its own. This can lead to the loss of unsaved data if the user is away from the computer when the updates are installed. Service Pack 2 enables the firewall by default. It also adds increased memory protection to let the operating system take advantage of new No eXecute technology built into CPUs such as the AMD64. This allows Windows XP to prevent some buffer overflow exploits.
On April 8, 2014, extended support of Windows XP ended. As this means that security vulnerabilities are no longer patched, the general advice given by both Microsoft and security specialists is to no longer use Windows XP.
