Companies and individuals heeded this week's warning — some may call it "hype" — about a file-destroying computer worm known as "Kama Sutra," helping minimize its damage Friday, security experts said.
One Italian city shut down its computers as a precaution, but otherwise the worm's trigger date arrived with relatively few reports of problems.
For days, experts warned that the worm could corrupt documents using the most common file types, including ".doc," ".pdf," and ".zip." It affects most versions of Microsoft Corp.'s Windows operating system, prompting the software giant to issue a warning Tuesday.
Hundreds of thousands of computers were believed to be infected, but security vendors say many companies and individuals had time to clean up their machines following the alarm, carried by scores of media outlets, including The Associated Press.
For Milan, Italy, though, the discovery came too late. Technicians switched off 10,000 city government computers after discovering the infection Thursday and deciding they didn't have enough time to clean the machines.
"It has spread to all our computers," said Giancarlo Martella, Milan's councilman for technological innovation and public services. "Knowing how destructive it is, we turned off all personal computers to avoid losing our data."
Only the municipality's registry office had been kept open because its "passive terminals" don't store data, Martella said, adding he hoped the computers would return to normal by Monday.
The worm — called "CME-24" but nicknamed after the Hindu love manual Kama Sutra because of the pornographic come-ons in e-mails spreading it — also tries to disable anti-virus software, but vendors have generally posted updates that should protect users.
Assuming the computer's calendar settings are correct, users can also avoid the worm by leaving their machines off until Saturday, although the worm is set to trigger again on March 3.
Security vendors Trend Micro Inc. and CA Inc. both assessed the overall risk and distribution as low. The worm wasn't designed to spread any more quickly Friday. Rather, Friday was the first trigger date for the file-destroying code.
Ajit Pillai, India's manager for U.S. security firm Watchguard Technologies Inc., said about 10 percent of his customers in the country had the worm, but they "followed the remedies and managed to avoid any problem."
"We didn't have to do any firefighting today," Pillai said.
So was the public bamboozled by the warning?
Hardly, experts say.
"The importance of media attention from an awareness and educational standpoint has been a very good thing," said Marc Solomon, director of product management at security vendor management McAfee Inc. "It alerts users to what may have happened and the destruction that could have occurred."
Call it hype if you wish, but "the hype was probably what prevented the disaster from happening," said David A. Milman, chief executive of the Syracuse, N.Y.-based Rescuecom.
He said his U.S. computer-repair chain initially saw a 20 percent increase in call volume, but mostly from customers seeking reassurance.
Security experts benefited from advance warning. The worm has been circulating for weeks but is set to destroy files only on the third day of each month. That gave vendors time to update their products and warn customers.
It's possible virus writers next time will have the file destruction start immediately, but that could also blunt a worm's ability to spread, said Ken Dunham, director of the rapid response team for VeriSign Inc.'s iDefense.
If files get wiped out right away, "you would notice that immediately, and people would start mitigating it," Dunham said. "If you let it build up, there's a much [greater] chance of spreading."