When it comes to anti-malware and security software for OS X, while tools like ClamXav and the recently released Sophos home edition for OS X are popular free options, another package that has fallen off the radar has been the relatively lightweight iAntivirus utility.
iAntivirus was originally developed by PC Tools in 2008 as a free Mac-specific antivirus tool, but the project did not last long and the latest version (1.36) was released in 2009 with no further updates. This has resulted in iAntivirus losing its relevance as a valid anti-malware tool for OS X users, and PC Tools has dropped support for it.
However, recent malware scares for OS X such as the Flashback "drive-by download," DNSChanger Trojan, and MacDefender scams have renewed interest in malware scanning utilities for OS X. In light of this, the Symantec company (makers of Norton AntiVirus for Mac) have taken up the iAntivirus reins and revived the name for its offering of a basic and free anti-malware utility for OS X users.
Even though the software does not have advanced features such as background scanning or on-access scanning that are available in its larger Norton AntiVirus utility for OS X, it can be used to run basic periodic scans for detecting and removing both Windows and Mac-based malware.
iAntivirus has a simple interface with options to scan the entire system, just your home folder, or specific files and folders of your choosing (drag-and-drop scanning is supported), but in addition it has the ability to scan for malware in files posted to your Facebook wall. If malware threats are found by the program, they will be quarantined and you can then choose to repair, delete, or restore the suspect files.
In brief testing of the software, when scanning it does take 100 percent of the CPU as it churns through files, though OS X distributes the task evenly among the system's CPU cores and should not be bogged down during scans. Between scans, the software idles at around 1 percent CPU usage. In terms of RAM usage, iAntivirus does have a sizable footprint at around 400MB; however, the tool is not meant to run persistently in the background so such resource usage will be of minimal impact to the system.
One minor confusion with the program is its option for scanning all files brings up an open dialog box similar to that when selecting the option to scan specific files and folders. One might expect the full system scan to be just that, without requiring you to select a starting point for the scan; however, this is a minor issue and the program otherwise has a smooth experience that should be intuitive. (UPDATE: Mike Romo from Symantec has clarified that this behavior is because of the sandboxing restrictions Apple is imposing for all App Store programs, and there is no way around it.)
A last word of note is that while Symantec's iAntivirus tool shares the same name as the past iAntivirus for OS X, it only shares the name and is not the same utility. Unlike the prior iAntivirus, Symantec's offering lacks a number of features, including active on-access protection, scheduled updating, scan customization, and scheduled scanning. Nevertheless, the software offers a simple and straightforward approach to quickly scanning your system should you feel the need to do so.
This offering from Symantec is great for OS X users who wish to have some form of anti-malware on their system but don't feel they need a full antivirus suite with a paid subscriptions, scheduling, and other features. This tool joins the likes of ClamXav and Sophos home edition as quick and free options for OS X users to help secure their systems from malware.
iAntivirus is built to run in OS X 10.6 or later, requires 2GB RAM, and is available exclusively on the Mac App Store as a 180MB download.