Hi all
I think my take on most
CURRENT (and I mean Current) FREE / Home type of AV software is well known -- I tend to think that around 90% of it is just junk using an outmoded technology attempting to find viruses on your machine AFTER the machine has already been infected.
These days most danger comes from activities that you do in your browser as I've posted elsewhere on the site.
A lot of these types of attacks using clever embedded code that your browser runs are quite difficult to stop - and after the code has been executed there is absolutely no trace that anything untoward was ever done on your machine - even if your entire spare drive has had porno loaded on to it

.
AV software needs to concentrate far more on catching these types of attacks -- it's relatively simple to scan for "nasties" in a typical downladed .exe or .dll file -- but how would you find a virus for example embedded in an MP3 file - especially if the code is built up dynamically by an external program which knows that it's stored an mp3 on your system with an embedded codex.
For example it can read the file and build up machine code from the contents of the mp3 file - all compressed music files will contain "artifacts" - so the AV software can't compare an mp3 file against a database of known viruses. Compression ratios / tagging info etc etc are usually fairly unique for each user.
My malware would be able to read say records 3,9,41, 22 etc in the file - take the first 4 binary bytes to build up my "bootstrap program" and then execute it - all dynamically. - Not too hard to do actually.
In addition to a previous post I made incorporating Malware 101, here's a snippet from Lesson 2.
To do real damage on a computer you only need to run what is known as a bootstrap type program --very few bytes needed . A legitmate example is of course the boot process.
This is essentially how the boot process works
1) the computer executes one instruction at adress xxxx (this is in the hardware bios)
2) this instruction tells computer to read 1 sector of disk into memory and start executing code from the address read in
Now you've got a "classical" program which can start to load the rest of the OS.
So your "Malware" only needs to consist of 2 simple instructions
the bootstrap - reads instruction either from a remote web site or build it up from data stored on the users machine
and then in 2) it tells the machine to execute code on website xxxx or whatever.
It's not quite that simple but you can see what I mean. --After instruction 2) has been executed there's no trace that it ever existed - hence will be missed by typical "classical AV.
I think that a lot of work needs now to be done by AV companies to combat these types of threats.
If you have a logger in your router that logs all IP addresses visited - switch it on as these are ilmost impossible for external users to hack into these hrdware logs.
Basic "Virus protection" is just that -- very basic and will only prevent attacks against programs you actually run yourself on your machine. Most don't protect against carefully embedded code initiated by "3rd parties" on remote web sites.
Cheers
jimbo