Defender conflicts?

[Alan D]

Here's a question that came up in another discussion to which I don't have
an answer. It concerns possible conflicts between running Defender with rtp
alongside other antimalware products.

I run Defender together with the AVG Internet Security suite. Effectively
that means that AVG Antimalware is running its resident shield alongside
Defender's rtp. I've been running this combination since October 2006 and
have experienced no difficulties:
1. On the one occasion that AVG intercepted an exploit.ani file, Defender
didn't interfere in any way with AVG's action.
2. If I open a file with Task manager open, I see AVG resident shield move
into action followed by Defender. They scan, then go quiet. No errors. No
fps.
3. Defender regularly flags up system changes with no interference from AVG.

I thought this was all good news, but it has been suggested that I may be
misleading myself: and that if both Defender and AVG detected the same piece
of malware, then there may be conflict between them that would allow the
malware through. The only way to test this as far as I can see, would be to
throw malware at a computer with the two programs running and see what
happens - something I'm not in a position to attempt.

Can anyone comment on this, please? To what extent is Defender designed to
run, in rtp, along with other antimalware products?

 

[Dave M]

Doing that can result in conflicts, but not necessarily. I suggest you
throw the EICAR test file at it and see what happens on your security
configuration, because EICAR should be detected by both. Watch task, or
process manager if you have it, while you do that for elevated CPU
particularly. I've yet to encounter that specific problem with multiple
RTPs, but then again I don't get much malware so I'm probably not a very
good test case.
http://www.eicar.org

 

[Robinb]

i did the test and AVG antivirus comes up and grabs it before Windows
Defender does on all the computers I am running both of them (7). I have
not tried it yet on vista- will try that later today

robin

 

[Alan D]

You folk are amazing. I ask a question to which I thought I'd only get
'maybe' answers - but no. Up comes Dave with a simple and elegant test, with
warnings about signs to look for; and then here goes Robin, diving in to
apply the test in practice and reporting back before I even have time to
blink.

Just give me a few moments to stand back and admire. And say thank you, of
course, to both of you.

 

[Alan D]

Afterthought:
Robin, the discussion I was referring to is in progress in the
SuperAntispyware forum, in this thread:
http://forums.superantispyware.com/viewtopic.php?t=853
If you feel inclined to report your findings there, it would be a useful
contribution, I think.

 

[Dave M]

No problem Alan, you're quite welcome. I'm always watching out for
conflicts of that sort, and my Norton's always grabs it before sleepy
Defender wakes up... LOL. Turning off my A-V does let Defender do his
thing, however, I didn't see any problem with AVG anti-spy trial either
when RTP was still active on it.