According to the latest edition of Symantec's Internet Security Threat Report, malicious hackers are increasingly using bot-networks, modular malicious code and targeted attacks on web applications and web browsers. These bot-networks can be used not only to spread malicious code, but to send spam or phishing messages, download adware and spyware, launch denial of service attacks, or harvest confidential user information. On average, Symantec monitored 1,402 DoS attacks per day in 2005, a 51 per cent was increased over that recorded in the first half of 2005. Crackers are now target home users for cash. Consumers at home are now on the main target of malicious hackers intent on inspiring themselves. Vulnerabilities are happen in desktop applications. Crackers are using a range of methods excusing detection and remain on infected systems for longer period. The most popular attack targets are Client-side applications such as web browsers and email clients. For example the cracker spread the spam, the most common method that spammers use is via open relays. The hackers scan the server and then send a message to a not reusable target address. Then after all this complete they can easily spread the spam broadly. For those users who did not update their PC randomly using anti-virus or anti adware and spyware, the risks to be detected are increased.

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