What Happens During A Scan - Symantec 10551441 - AntiVirus Corporate Edition Client Manual

Protecting your computer from viruses and security risks 51
Scanning for viruses and security risks
You can perform a scan while you wait or schedule a scan for when you are away
from your desk.

What happens during a scan

During a scan, Symantec AntiVirus searches the computer's memory, boot
sector, and selected drives for virus and security risk signatures that identify an
infection or the presence of a risk.
Computer memory
Symantec AntiVirus searches the computer's memory. Any file virus, boot
sector virus, or macro virus may be memory-resident. Viruses that are memory-
resident have copied themselves into a computer's memory. In memory, a virus
can hide until a trigger event occurs. Then the virus can spread to a floppy disk
in the disk drive, or to the hard drive. There is no known way to clean viruses
that find their way to memory. However, you can remove a virus from memory
by restarting your computer when prompted.
Boot sector
Symantec AntiVirus checks the computer's boot sector for boot viruses. Two
items are checked: the partition tables and the master boot record.
Floppy drive
A common way for a virus to spread is through floppy disks that are left in a disk
drive when a computer is being turned on or off. If a floppy disk is in the disk
drive when a scan is started, Symantec AntiVirus searches the boot sector and
partition tables of the floppy drive. If a floppy disk is in the disk drive when you
turn off your computer, you are prompted to remove the disk to prevent possible
infection.
Selected files
Symantec AntiVirus scans individual files. For most types of scans, you select
the files that you want scanned. Symantec AntiVirus uses pattern-based
scanning to search for traces of viruses, called patterns or signatures, within
files. Each file is compared to the innocuous signatures that are contained in a
virus definitions file, as a way of identifying specific viruses. If a virus is found,
by default Symantec AntiVirus attempts to clean the virus from the file. If the
file cannot be cleaned, Symantec AntiVirus quarantines the file to prevent
further infection of your computer.