Scan Your Computer - Part II

Tip:

Scan Your Computer

Antivirus for Mac can protect you with three major kinds of scans:

Scan Type

Description

Real-time Scanning

This feature checks for malicious software whenever your Mac receives, opens, downloads, copies, or modifies a file. You should always keep this feature enabled.

"On-Demand" Scanning

You can make Antivirus for Mac scan some or all of the files on your Mac whenever you want. This kind of scanning can find malicious software already inside files that you have not yet used. The time needed to finish this kind of scan depends on the number of files involved and the specifications of your Mac.

Scheduled Scanning

You can set a schedule for Antivirus for Mac to check some or all of the files on your Mac. Just like "on demand" scanning, this kind of scanning can find malicious software already inside files that you have not yet used. The time needed to finish this kind of scan depends on the number of files involved and the specifications of your Mac.

Scanning Your Mac

You can make Antivirus for Mac check all (or just some) of the files on your Mac for malicious software. The time needed to finish the scan depends on the total number of files checked, as well as the hardware specifications of your Mac.

  1. Click the Antivirus for Mac icon near the top right corner of your screen, and then select Open Trend Micro Antivirus for Mac...
  2. Click Scans on the left side of the window, and then select one of the three options shown:
    Option Description

    Smart Scan

    Checks only the files most likely to contain malicious software. A Smart Scan will usually finish more quickly than a full scan, and can generally find the same malicious software.

    Custom Scan

    Checks specific files or folders on your Mac. Click Choose Files or Folders... to specify which files to scan. You might want to select this option to check the files on a removable USB drive, for example. By the way, you can also drag any file onto the Antivirus for Mac window to scan it for malicious software.

    Full Scan

    Checks all the files on your Mac. It will generally take longer than the other scans, but should find any hidden malicious software.

Compressed File Scans

Compressing a file sent from one computer to another reduces the burden on the network connection. For large files, that can often save a lot of time. Unfortunately, malicious software can easily hide inside compressed files, so Antivirus for Mac must take extra precautions when dealing with them.

Upon finding a compressed file, Antivirus for Mac will first try to unpack its contents and scan the files inside. If it finds more compressed files within the first one, Antivirus for Mac will unpack those as well.

Real-time scans will check up to three layers of compression, while scheduled and on-demand scans can examine up to five layers. Because these files more often pose a risk, you should make Antivirus for Mac quarantine or delete compressed files that it cannot scan or clean.

Layers of Compression

Most compressed files contain only a single "layer." A compressed file that itself contains other compressed files has "multiple layers."

For example, suppose a compressed file called pets.zip contains cats.docdogs.zipbirds.doc, and fish.doc. In this case, dogs.zip is also a compressed file containing beagles.doc and poodles.doc.

When considering the entire pets.zip file, cats.docdogs.zipbirds.doc, and fish.doc are in the "first layer" of compression. beagles.doc and poodles.doc are in the "second layer" of compression, hidden inside dogs.zip.

Antivirus for Mac can find malicious software lurking inside multiple layers of compressed files.

Compression Types Scanned

Antivirus for Mac can check the following types of compressed files:

File Type

Description

.ACE

Created by WinAce archiver

.ARJ

ARJ compressed archive

.BIN

MacBinary encoded file or CD image

.BZ2

UNIX BZip2 compressed file

.CAB

Microsoft cabinet file

.EML

Microsoft Outlook Email file

.GZ; .GZIP

UNIX or GNU ZIP archive

.HQX

Macintosh BinHex encoded file

.LHA

LHarc compressed archive

.MHT

Multipurpose Internet mail HTML file (web archive file)

.RAR

Compressed file created by WinRAR

.TAR

Backup tape archive

.TD0

Teledisk disk image

.UU

UU-encoded data file

.Z

UNIX compressed archive

.ZIP

Compressed file created by PKzip or 7-zip