Increasing publicity and accessibility to virus-removal tools have checked the spread of the Sasser computer worm, but family broadband users are still at risk.

According to the latest daily report by the Beijing Rising Technology CorpLtd, an anti-virus software producer, an increasing number of family broadband users are calling up for technical support.

There were 4,560 inquiries in the 24 hours to 2 pm on Sunday. "Family PC users have relatively limited channels for technical solutions," said Wang Jianfeng, vice-president of the company's department that is responsible for providing technical support to customers.

"Compared with company users, they usually lack basic knowledge in terms of guarding against computer viruses."

While in-house information technology professions can take measures to protect companies against computer viruses, family broadband users are easy targets as they spend long periods of time surfing on the Internet without proper protection against worms.

Monday's report did not give exact figures for the number of family or company PC users who called. Up to 30 percent of the 6,536 callers on the previous day were company PC users.

Sources from the Tianjin-based National Computer Virus Emergency Response Center said Monday that Sasser had passed its peak, as the number of newly reported cases was dropping.

The computer worm was detected on May 1 after hitting many family PCs in China. But the nation was celebrating the Labor Day holiday, prompting experts to caution that there could be a resurgence during the weekend just passed, as people went back to work.

The worm attacks through a flaw in Microsoft's recent versions of its Windows operating systems including Windows 2000, Windows Server 2003 and Windows XP.

Infected computers are forced into an unstoppable pattern of shutting down and rebooting -- but no lasting harm to computers has been recorded.

An 18-year-old German schoolboy confessed on Saturday that he created the malicious virus, which has hit millions of computers worldwide.

However, his arrest does not necessarily mean the end of Sasser's spread. It is the third major computer worm for the year.

Computer engineers have suspected that the program codes of the virus have already been uploaded onto the Internet, allowing virus program writers to create new variants.

So far, four variants of the virus have been detected, with the last being intercepted on Sunday afternoon.

Since Wednesday, the Beijing Rising Technology Corp Ltd has distributed 500,000 compact disks for free, which contain tools to protect computers.

Another major Chinese anti-virus software producer, the Beijing Jiangmin Software New Technology Co Ltd, has given out 600,000 such disks.

PC users can download pack from the Microsoft website to protect themselves against the worm or remove its variants.

(China Daily May 11, 2004)