“Malware” is a coinage from “malicious” and “software”. This software infects computers which are connected to the Internet, and conducts remote control of them to transmit spam, steal information or commit other criminal activities.
Malware infection leads to a number of troubles, including data deletion and computer breakdown. If the damage is more severe, restoration may require reformatting of the computer's hard disk and re-installation of Windows OS and other application software.
Malware infection leads to undetected theft of personal information.
Some malware collects IDs and passwords which are used for net banking and e-shopping, by stealing the computer keyboard's activity. Another kind of malware collects information stored in a computer and transmits the information to an outside location.
Furthermore, malware might include such functions as remote operation of external peripheral equipment including cameras or microphones, to monitor user's actions.
A malware-infected computer may allow a malicious party to make the computer connect automatically to certain servers on the Internet and then receive remote control instructions from the servers. The computer then becomes part of a network to be an illegal botnet.
A malware-infected computer under control of a malicious person may be used to send large volume of mail to specific companies or government offices, shut down the websites of these organizations and send mail leading to phishing sites .
As described below, there are various ways in which malware infection happens.
Recently, the major infection route has been changing from traditional network-based infection route to web based infection (drive-by downloads) and the way of malware infection has been getting more sophisticated.
This malware infection route is through accessing malware- embedded websites and downloading malware.
Sometimes net surfing results in malware infection and it is difficult for the Internet user to be aware that infection has occurred.
By clicking on a URL in a mail, users are guided to a website which intends to infect a computer with malware.
Defects in Windows and other basic software are exploited to infect a computer with malware.
Malware is embedded within the attachment of a mail, or infection happens after clicking on the attachment file.
Infection occurs through external media, such as USB memory, digital cameras, music players, etc.
Those malware has recently abound which is created to commit a crime.
Such crime includes theft of IDs or passwords, or outright theft of money -or includes conduct of attacks against countries or organizations holding specific thoughts.
Tools for creating malware are publically available, so that even an attacker without a high degree of knowledge can rather easily create malware. Therefore, a wide variety of malware is being created and distributed every day.
Recent malware does not activate for some time after infection, to ensure that the computer user is not aware its infection. Therefore, detection of malware infection is difficult.
After infection, some malware will automatically update itself and add new functions, so that the functions continue to change, making it more difficult for antivirus software to search for the malware.