The attacks, waged over the Internet, made computers crash and caused what is known as the "blue screen of death"--a reference to the blue screen that accompanies Microsoft's "fatal error" message.
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Educational institutions including the University of California campuses at Berkeley, Los Angeles, San Diego, and Irvine; the Twin Cities Campus of the University of Minnesota; the Massachusetts Institute of Technology; Cornell University; Princeton University; the University of Washington; the University of Texas at Austin; and the University of Wisconsin at Madison, a NASA research partner, also were targeted. A reported attack on computers at Northwestern University could not be confirmed.
Navy computers in Point Loma, California; Charleston, South Carolina; Norfolk, Virginia; and elsewhere also were affected, according to a report by the San Diego Union-Tribune.
The attacks were of the type known variously as "New Tear," "Bonk," or "Boink," according to Microsoft security product manager Jason Garms. Microsoft in January posted patches to protect against "New Tear" attacks.
Microsoft is working with affected NASA centers and educational institutions to hunt the source of the attacks. Some of the targeted institutions are enlisting the aid of the FBI, according to Garms. The FBI declined to comment on the matter.
Garms declined to specify which others in addition to the NASA, Navy, and university sites were attacked. But he did describe the targeted group as "a large cross segment of government sites and educational institutions."
Last night, Microsoft posted a security bulletin on the attack describing the problem and advising users to implement its fix.
MCI Communications also circulated a security announcement on the attack to its network customers, according to a systems engineer at Yale University. Yale did not report being targeted in the attack.
Systems were restored simply by rebooting the computers. In some cases, the computers were programmed to reboot automatically in response to the attack, so users returned to work this morning without any knowledge that their computers had been targeted.
"Denial of service" attacks prevent servers from answering network connections and can crash individual computers. In one form, for example, servers are fooled into thinking they are going to receive a certain type of data packet. When that particular packet never arrives, the servers hang up.
Systems administrators reported that some computers with patched operating systems did fend off the attack.
"There's a patch Microsoft has for it," said Ames Research Center computer security manager John Ray. "It hit some of our systems that didn't have the patch."
About 50 of Ames's approximately 3,000 computers were affected, Ray said.
At the Jet Propulsion Laboratory in Pasadena, California, spokesman Frank O'Donnell questioned whether the lab could have protected against the attack with a patch.
"Microsoft actually issues a steady stream of patches in the general area of network connectivity," O'Donnell said. "It's not certain to us at this point how this particular attack came in, so I don't think we can say with certainty that there's a patch that would have prevented this attack."
But Microsoft's Garms said preliminary evidence collected yesterday from the targeted sites suggested that the problem was of the same type the January fix addressed, and that only computers lacking the fix were affected.
"There's no new issue here," Garms said. "But many sites haven't secured up-to-date security patches."
O'Donnell said the matter was under investigation and that, pending a decision on the implementation of patches, a network protective solution had been imposed. He declined to specify what measures the JPL had taken.
O'Donnell stressed that no sensitive information affecting space missions was endangered during the attack and that all systems that control spacecraft were behind firewalls.
The attack comes as the nation's attention is focused on the issue of hacking after two California boys allegedly hacked computers at the Pentagon. Monday night's attack also coincided with testimony by Microsoft chief executive Bill Gates before the Senate Judiciary Committee regarding competitive practices in the software industry.
NASA sites reporting the attack are as follows: NASA Headquarters in Washington; Ames Research Center in California; Dryden Flight Research Center in California, Goddard Space Flight Center in Maryland; Independent Validation and Verification Facility in West Virginia; Jet Propulsion Laboratory in California; Kennedy Space Center in Florida, Langley Research Center in Virginia; Lewis Research Center in Ohio; Marshall Space Flight Center in Alabama; Moffett Federal Airfield in California; Stennis Space Center in Mississippi; Wallops Flight Facility in Virginia; and White Sands Test Facility in New Mexico.
Johnson Space Center in Houston did not send out an automated security incident report, according to Ames spokesman John Bluck.