another form of computer attack is virus

virus are designed to spread into other programs and can wreak havoc in a system

it modifying or destroying files and causing system crashes and program malfunctions

all of these

the password is different in each instance

the password is same in each instance

both (a) and (b)

none of these

are usually spread by users downloading viral programs from public bulletin boards or exchanging floppy disks containing an infection

are beneficial for program

both (a) and (b)

none of these

Trojan Horse

trap doors

both 1) Trojan Horse and 2) trap doors

none of these

prevention

practice of safe computing

purchasing unopened software from vendors

avoiding free or pirated copies from public sources