The rampant e-mail virus called Sobig.F has kept computer technicians hopping at Bay Area colleges and universities as they scramble to delete tens of thousands of junk messages and, in some cases, purge the virus from infected computers.

"We're so tired," Julianne Tolson with San Francisco State University's information technology department joked Friday afternoon. She said as many as 20 technicians had been scrambling all week to clean up the dregs of Sobig.F, which has been called the fastest-spreading e-mail virus of all time.

Since its debut on Monday, the virus has sent more than 100 million pieces of junk mail with subject lines such as "details," "wicked screensaver" and "thank you."

If the user opens attachments contained in the message, Sobig infects the host computer and resends itself to e-mail addresses found on the machine.

On Friday, Internet security specialists were able to block the virus from changing into a more dangerous form and federal officials continued their search for its creator.

SFSU has blocked as many as 75,000 suspicious e-mails in one day alone, said Phoebe Kwan, executive director of the IT division, but some messages did make it through and were ultimately opened by computer users.

Tolson, coordinator of consulting and training with the IT department, estimated that between 300 and 500 of the campus' approximately 5,000 computers have been infected by the virus, and technicians have purged Sobig.F from all but about 100 of them.

Other campuses have their hands full just dealing with the sheer volume of e-mails the virus has sent.

California State University, Hayward, spokesman Kim Huggett said the campus' technology help desk has received about 20 calls a day since Wednesday from users complaining they're receiving "returned message" e-mails from addresses they didn't write to in the first place.

"Our employees are savvy enough to know not to open attachments from senders they don't recognize, so we have not had a case that caused a computer to crash," he said. "Our information and computer services office is aware of the virus ... and are advising employees as well as students using any of our six or seven computer labs on campus to ignore those messages, delete the message and certainly not open the attachments."

Craig Lant, information systems security officer at the University of California, Berkeley, said the campus on Wednesday updated its anti-virus software to block Sobig.F and so far has been able to avoid server melt-downs and other major catastrophes.

"Aside from just the huge amount of e-mail we've had to deal with, we're holding our heads above water," said Lant, who estimated the campus network was hit with 40,000 to 50,000 e-mails the day the virus debuted.

Sobig.F hit just as the new school year began and thousands of students -- many of whom have e-mail accounts with the university -- returned to campus.

"It's not that I don't want the students here -- I love the students here," Lant said. "But it does make life more complicated when they're all arriving at the same time."

Earlier this month, Lant and his team scrambled to patch a flaw in the Microsoft Windows operating system that left hundreds of campus computers vulnerable to attack from outside hackers.

Jennifer Aries, spokeswoman for the Chabot-Las Positas Community College District, said the district's anti-virus software blocked Sobig-tainted messages and officials haven't experienced any problems.

"The ITS staff is constantly monitoring the virus checker and that's what prevents us from getting hit by these viruses," Aries said. "We haven't been infected by any of the other ones, either."