<font size="3">Sobig Virus Slows, but Aims to Build Robot Network </font>

SAN FRANCISCO (Reuters) - The culprit behind the fast-spreading Sobig.F virus is expected to try again in coming weeks to create a vast network of zombie computers to carry out Internet attacks, security experts warned on Saturday.

"He wants to build up a (robot) net by creating zombie machines he can control," said Vincent Weafer, senior director of Symantec Corp.'s Security Response center.

An automated attack that had been set for Friday at noon California time was thwarted by government and security industry experts before it could take control of some 100,000 infected computers and possibly cripple the Internet.

Sobig.F was released last Monday on a sex-oriented Internet discussion group, infecting computers when users clicked on what appeared to be nude pictures, experts from several security companies who had seen the site said.

Prior versions of Sobig.F -- the F is the sixth variation of the Sobig virus that first began appearing in January -- appeared to test different means of self-replication, with each of the six versions becoming more sophisticated, Weafer said.

"There has been a sequence of different worms to create a greater goal -- dynamic (robots) that can update themselves," Weafer said.

full story: Yahoo! News