Originally Posted by bwhazel
It's interesting how Apple are advocating the use of more than one AntiVirus application. I am a native Windows and PC user, although I am writing this from my new MacBook White(!), and Windows users are advised to only use one virus scanner at a time as multiple ones installed can disable one another!
Also, as a native Windows user, my PC, Windows Tablet, Mac mini, and MacBook all have virus scanning software - it gives me piece of mind that I am safe!
I have spent many long hours cleaning malware from Windows machines - and I can tell you for sure that it often takes multiple products to do the job effectively - and in some cases those tools each have to be run multiple times to clean everything. Some of them do not search the system restore volumes for example. What you have to watch for is folks who don't know better and install so many different anti virus, anti spyware, anti etc etc etc that their system ends up spending 90% of its CPU cycles scanning files. I have personally seen cases where Norton was disabled by a virus. I have also seen too many cases where a user had anti-virus software that expired a year ago and was doing little to no good.
On Mac - the last time I saw an actual factual in the wild virus was around 1990 and that was cdev which made exactly one copy of itself onto each mounted volume (hard drive, floppy) and caused no harm. I did have a virus scan running on my Mac OS X systems until recently when I found that it was causing frequent runaway CPU usage and so I have turned them off for now.
On the PC side there is a ton of software out there that will scan for free but not clean unless you pay - or some which can only be run manually unless you pay. I think most ISPs now provide free Anti-Virus (for PC at least) so that is a good place for most folks to start. My standard procedure on any PC machine I work on is to do the following:
1. get rid of any and all junk the user already had running.
2. make sure all windows and office updates and java, adobe, etc updates are done
3. run Malwarebytes.org anti-malware (found 1 thing on my work PC that enterprise Trendmicro Officescan missed)
4. run safety.live.com scanner (mostly I use the registry repair but will run the full scan on a machine that is suspect)
5. run housecall.trendmicro.com (can take a very long time on a slow machine which has not had regular maintenance)
6. install and run whatever your ISP provides - I use CA - but only their Anti-Virus and Anti-Spyware (most anti-spam software is kind of a pain and the firewall takes a lot of hands on to get configured properly)
7. run a disk clean up (and remove restore points)
8. run a disk defrag (often multiple times)
9. run everything again to be sure
On the Mac side
1. run Apple Software Update every so often
2. run Disk utilities Repair Permissions after major updates
3. that's about it - once a year or so hook the machine up in Firewire target mode and run DiskWarrior and defrag (if I remember to do it)
Years ago there was a product called White Knight (or at least that is the way I remember it) for pre-OS X Macs - that scanned for "virus like activity" which means things like a program writing over its own code - or an application writing to a system file. The basic idea was that properly coded software that has no malicious intent should not be doing those things - there were 6 separate categories. The main benefit was that it could catch a previously unknown virus without needing to know a single bit of the code responsible for the virus. One of the major problems with it was that nearly every piece of software published by Microsoft violated one or more of those rules just to function normally - and so you would have to grant MS software permission to do things that proper code should not be allowed to do - which then opened the door to a virus which either presented itself as the MS software or infected the MS software being allowed to do exactly the things you do not want a virus to do. There was another free anti-virus tool many years ago on Mac that I don't recall the name of, published by a team at a university I think, who finally gave up on it in part because the incidence of any actual virus activity on the Mac in the 1990s was very nearly non-existent. I did use Symantec and Norton tools for years through OS 9 - but ran into way too much trouble with Norton on early OS X to keep it.
To those without AV on Windows - I tried that on a couple slower Windows 2000 computers thinking that perhaps the way they are used and with older versions of IE etc the risk would be low - guess again - I am now in the process of making sure that every PC I am responsible for has a decent set of anti-malware tools running.