MANILA, Philippines--The number of "bot-infected" computers in the country has risen significantly as a consequence of the increase in broadband penetration, according to Symantec.

Manila now ranks sixth among cities in the Asia Pacific and Japan region with the highest number of infected PCs, based on Symantec's latest regional Internet Security Threat Report (ISTR) covering July to December 2007.

Manila was ranked 83rd in the previous ISTR, which is released by Symantec every six months.

On a per country basis, the Philippines ranks ninth, behind Malaysia and Singapore among countries in Southeast Asia.

Based on Symantec's estimates, there were more than 7,600 bot-infected PCs in Asia Pacific and Japan, which represents around 12 percent of the global total.

China still accounts for more than 40 percent of these infected PCs although its percentage has declined significantly from nearly 80 percent in the previous ISTR.

China's progress, however, translated to attackers targeting other countries. Kuala Lumpur, for example, now has the highest number of infected PCs topping Beijing, Bangkok, Guangzhou and Hong Kong.

Richard Velasco, senior technical consultant for Symantec Philippines, attributed the increase in the number of infected PCs to the growth in the number of broadband subscribers.

PCs normally get infected with these malicious codes when downloading files or browsing infected Web pages. Attackers then use these hundreds of bots to target host computers elsewhere.

"The code can just sit in these PCs until activated, but having these infected machines provides attackers greater access to their targets," said Velasco, in a briefing discussing Symantec's latest report.

"Bottom line is, we don't want local PCs being used by the bad guys," he said.