In one embodiment, an antivirus mechanism (e.g., antivirus program) in a computer initiates shielding procedures in response to a triggering event indicative of a presence of a virus in the computer, the virus being of a type not recognized by the antivirus program. The shielding procedures advantageously protect important components of the computer while the antivirus program does not have the requisite antidote to directly deal with the virus.