Malware

Malware, short for malicious software, consists of programming (code, scripts, active content, and other software) designed to disrupt or deny operation, gather information that leads to loss of privacy or exploitation, gain unauthorized access to system resources, and other

In law, malware is sometimes known as a computer contaminant, for instance in the legal codes of several U.S. states, including California and West Virginia. The prevalence of malware as a vehicle for organized Internet crime, along with the general inability of traditional anti-malware protection platforms (products) to protect against the continuous stream of unique and newly produced malware, has seen the adoption of a new mindset for businesses operating on the abusive behavior. The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code.

Software is considered to be malware based on the perceived intent of the creator rather than any particular features. Malware includes computer viruses, worms, trojan horses, spyware, dishonest adware, scareware, crimeware, most rootkits, and other malicious and unwanted software or program. Internet: the acknowledgment that some sizable percentage of Internet customers will always be infected for some reason or another, and that they need to continue doing business with infected customers. The result is a greater emphasis on back-office systems designed to spot fraudulent activities associated with advanced malware operating on customers' computers. Malware is not the same as defective software, that is, software that has a legitimate purpose but contains harmful bugs. Sometimes, malware is disguised as genuine software, and may come from an official site. Therefore, some security programs, such as McAfee may call malware "potentially unwanted programs" or "PUP". Though a computer virus is malware that can reproduce itself, the term is often used

erroneously to refer to the entire category.

Purposes

Many early infectious programs, including the first Internet Worm and a number of MS-DOS viruses, were written as experiments or

pranks. They were generally intended to be harmless or merely annoying, rather than to cause serious damage to computer systems. In some cases, the perpetrator did not realize how much harm his or her creations would do. Young programmers learning about viruses and their

techniques wrote them simply for practice, or to see how far they could spread. As late as 1999, widespread viruses such as the Melissa virus and theDavid virus appear to have been written chiefly as pranks. The first mobile phone virus, Cabir, appeared in 2004. Hostile intent related to vandalism can be found in programs designed to cause harm or data loss. Many DOS viruses, and the WindowsExploreZip worm, were designed to destroy files on a hard disk, or to corrupt the file system by writing invalid data to them. Network-borne worms such as the 2001 Code Red worm or the Ramen worm fall into the same category. Designed to vandalize web pages, worms may seem like the online equivalent to graffiti tagging, with the author's alias or affinity group appearing everywhere the worm goes. Another strictly for-profit category of malware has emerged in spyware -- programs designed to monitor users' web browsing, display unsolicited advertisements, or redirect affiliate marketing revenues to the spyware creator. Spyware programs do not spread like viruses; they are, in general, installed by exploiting security holes or are packaged with user-installed software, such as peer-to-peer applications.

Backdoors

A backdoor is a method of bypassing normal authentication procedures. Once a system has been compromised (by one of the above methods, or in some other way), one or more backdoors may be installed in order to allow easier access in the future. Backdoors may also be installed prior to malicious software, to allow attackers entry. The idea has often been suggested that computer manufacturers preinstall backdoors on their systems to provide technical support for customers, but this has never been reliably verified. Crackerstypically use backdoors to secure remote access to a computer, while attempting to remain hidden from casual inspection. To install backdoors crackers may use Trojan horses, worms, or other methods.

Vulnerability to malware

In this context, as throughout, it should be borne in mind that the “system” under attack may be of various types, e.g. a single computer and operating system, a network or an application.

Various factors make a system more vulnerable to malware:

 Homogeneity: e.g. when all computers in a network run the same OS, upon exploiting one, one can exploit them all.

 Weight of numbers: simply because the vast majority of existing malware is written to attack Windows systems, then Windows systems, ipso facto, are more vulnerable to succumbing to malware (regardless of the security strengths or weaknesses of Windows itself).

 Defects: malware leveraging defects in the OS design.

 Unconfirmed code: code from a floppy disk, CD-ROM or USB device may be executed without the user’s agreement.

 Over-privileged users: some systems allow all users to modify their internal structures.

 Over-privileged code: some systems allow code executed by a user to access all rights of that user.

How to protect yourself from Malware?

Prevention is a vital point when our equipment to protect against possible infection of somekind of malware and for this there are three vital points:

• Antivirus program.
• A firewall program.
• A "little" common sense.

if you want know more, check this links:

http://en.wikipedia.org/wiki/Malware

http://www.infospyware.com/articulos/que-son-los-malwares/