The hacking and defacing of websites is on the rise, with site spoiling up five-fold this year.

The number of vandalised websites recorded by defacement archive jumped in 2001 to 22,379 — over five times more than the 4,393 incidents logged in 2000.

The increase in defacements is mostly the work of Brazilian cybervandals, according to Fredrik Ostergren, a Sweden-based security analyst and spokesman for Ostergren also said that more internet users in general are trying out tools to hack into websites.

"Many of the defacers we have in the scene today are located in Brazil," he said in an email response to a reporter's questions. "One of the reasons for the increase is more people getting connected to the internet, especially in Brazil."

A defacer is a hacker who breaks into a web server and vandalises the website by replacing or altering the front page. has been tracking defacements since 1998 and offers snapshots of victim's websites as well as security analyses and statistics.

The number of defacements was especially high in April and May, with 3,003 and 3,431 sites altered respectively.

US and Chinese hackers were said to be fighting a 'cyberwar' in those months after a US spy plane crash-landed in China on 1 April, and the FBI warned at the time of increased attacks by Chinese hackers.

Most popular among cybervandals are well-known sites. Over 60 percent of the marred websites logged to date by were hosted on a Microsoft Windows server, and 20 percent on servers running Linux.