The e-mail message advised students to update their anti-virus programs in order to test for the virus. It also provided cleaning instructions for students whose computers had already been infected.

Since then, the virus has also surfaced in Adams House, leading House UAs there to send an e-mail message to residents warning them of the virus.

Adams resident Malka S. Resnicoff '00, whose computer contracted the virus, said she was confused by these notifications.

"I heard from Adams House people that it affects the hard drive," Resnicoff said. "I also heard it could cause macro quirks."

A macro is a set of instructions that controls tasks within a given application or system. "W97M/Thus" is classified as a "macro virus," which means it causes damage with a set of instructions for a particular program.

Despite the confusion, Resnicoff said she followed the series of instructions presented in the e-mail messages from her UAs and quickly ridded her computer of the virus.

"It was really easy," she said.

Osterberg also stressed the importance of updating the anti-virus programs on students' computers. He said one such anti-virus program, Dr. Solomon's Anti-Virus Toolkit, is available for free use on FAS public servers.