[isapros] Re: Port Scan
- From: "Greg Mulholland" <gmulholland@xxxxxxxxxxxx>
- To: <isapros@xxxxxxxxxxxxx>
- Date: Wed, 26 Jul 2006 08:08:45 +1000
oh ye of little faith.. as my old man used to say..
as long as i know that the firewalls doing its job and is working correctly
i can worry about the next thing.
Greg
----- Original Message -----
From: "Amy Babinchak" <amy@xxxxxxxxxxxxxxxxxxxxxxxxxx>
To: <isapros@xxxxxxxxxxxxx>
Sent: Wednesday, July 26, 2006 7:26 AM
Subject: [isapros] Re: Port Scan
http://www.toolzz.com/ISATools/2000tools.htm
It may be a waste but you forgot that I feel better now. That's
something. Maybe it's a girl thing.
I also have a habit of creating protocols for stuff that shows up as
unidentified traffic. I suppose that's a waste too because ISA handles
it whether it has a name or not. But it makes it easier on me.
Now I can look at the logs and when I see Denied and the rule is Drop
This Connection, then I know what it is. Just like when I see HP Printer
Broadcast protocol in the logs, I know what that is. (and how to stop
it)
-----Original Message-----
From: isapros-bounce@xxxxxxxxxxxxx [mailto:isapros-bounce@xxxxxxxxxxxxx]
On Behalf Of Jim Harrison
Sent: Tuesday, July 25, 2006 5:17 PM
To: isapros@xxxxxxxxxxxxx
Subject: [isapros] Re: Port Scan
..where?
-------------------------------------------------------
Jim Harrison
MCP(NT4, W2K), A+, Network+, PCG
http://isaserver.org/Jim_Harrison/
http://isatools.org
Read the help / books / articles!
-------------------------------------------------------
-----Original Message-----
From: isapros-bounce@xxxxxxxxxxxxx [mailto:isapros-bounce@xxxxxxxxxxxxx]
On Behalf Of Amy Babinchak
Sent: Tuesday, July 25, 2006 13:58
To: isapros@xxxxxxxxxxxxx
Subject: [isapros] Re: Port Scan
I found the script available on ISAtoolz. Never heard of that site
either.
Amy
-----Original Message-----
From: isapros-bounce@xxxxxxxxxxxxx [mailto:isapros-bounce@xxxxxxxxxxxxx]
On Behalf Of Thomas W Shinder
Sent: Tuesday, July 25, 2006 4:54 PM
To: isapros@xxxxxxxxxxxxx
Subject: [isapros] Re: Port Scan
I think Tsu added quite of bit of intelligence into the script :P
Thomas W Shinder, M.D.
Site: www.isaserver.org
Blog: http://blogs.isaserver.org/shinder/
Book: http://tinyurl.com/3xqb7
MVP -- ISA Firewalls
-----Original Message-----
From: isapros-bounce@xxxxxxxxxxxxx
[mailto:isapros-bounce@xxxxxxxxxxxxx] On Behalf Of Thor (Hammer of
God)
Sent: Tuesday, July 25, 2006 3:52 PM
To: isapros@xxxxxxxxxxxxx
Subject: [isapros] Re: Port Scan
Yep--- was there any "intelligence" in the blocking rule, or could
someone do a simple port scan of the external interface from the NAT'd
internal LAN to automatically block all internal traffic? ;)
t
On 7/25/06 1:42 PM, "Jim Harrison" <Jim@xxxxxxxxxxxx> spoketh to all:
> Yep - total agreement and this was the core of the "fight"
way back when.
> Not only that, but any automated "rule builder" can be used
a great DoS
> mechanism.
>
> -------------------------------------------------------
> Jim Harrison
> MCP(NT4, W2K), A+, Network+, PCG
> http://isaserver.org/Jim_Harrison/
> http://isatools.org
> Read the help / books / articles!
> -------------------------------------------------------
>
>
> -----Original Message-----
> From: isapros-bounce@xxxxxxxxxxxxx
[mailto:isapros-bounce@xxxxxxxxxxxxx] On
> Behalf Of Thor (Hammer of God)
> Sent: Tuesday, July 25, 2006 12:52
> To: isapros@xxxxxxxxxxxxx
> Subject: [isapros] Re: Port Scan
>
> .02:
>
> It seems like a total waste of time to respond to "scan
attacks" with a block
> script, as everything is being blocked anyway- just not
with an explicit
> "block" rule. The presence of the "scan" alert tells you
that ISA is doing
> its job - AFAIAC, no other action is even necessary. If
there is some
> incessant attack from a persistent IP hammering away at
published services and
> you just don't want to see it, then put in a deny rule. If
it is a bandwidth
> issue (like when I was getting Code Red attacks all day,
every day) then block
> it on the ISP side. But that costs money for that service,
typically.
> However, it does work.
>
> If it is in the realm of "identified" attacks ala my
"strikeback" model, then
> that is a different thing- and something that is deployed
in a completely
> different way to solve a different problem (lest someone
tried to use that
> against me ;). Port scans and "noise" traffic an safely be ignored.
>
> t
>
>
> On 7/25/06 11:58 AM, "Jim Harrison" <Jim@xxxxxxxxxxxx>
spoketh to all:
>
>> Think way back to your involvement with SBS in the Yahoo list.
>> It was how I got invited to join that list; the
BlockAttacker script
>> was being touted as the be-all, end-all to ISA port scan response.
>> I had to get really nasty (even for me) with the proponent of this
>> technique before he finally backed down.
>> He still regurgitates this nonsense (among other senseless
>> meanderings) from time to time, but it's an easy head-slap.
>>
>> For those not familiar, the BlockAttacker script was an
expansion of
>> the ISA 2000 alert action example that used the client IP
to create a
>> packet filter blocking the "offending host". While it provided an
>> excellent example of using ISA alert environment
variables, it turned
>> out to be a great DoS tool as well and we pulled it from
isatools.org.
>>
>> Unfortunately, there is one (TSu) individual who shall
remain nameless
>> (Tony
>> Su) who insists on singing the praises of this response
technique to
>> unsuspecting ISA admins. Luckily, he's not skilled enough
to sort out
>> how to port the script to ISA 2004 or we'd have more PSS
calls than we do
>> now.
>>
>> -------------------------------------------------------
>> Jim Harrison
>> MCP(NT4, W2K), A+, Network+, PCG
>> http://isaserver.org/Jim_Harrison/
>> http://isatools.org
>> Read the help / books / articles!
>> -------------------------------------------------------
>>
>>
>> -----Original Message-----
>> From: isapros-bounce@xxxxxxxxxxxxx
>> [mailto:isapros-bounce@xxxxxxxxxxxxx] On Behalf Of Amy Babinchak
>> Sent: Tuesday, July 25, 2006 11:21
>> To: isapros@xxxxxxxxxxxxx
>> Subject: [isapros] Re: Port Scan
>>
>> I don't know that joke. I think it was before my time on the list.
>> What's the block attacker script? Never heard of it.
>>
>> Amy Babinchak
>>
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: isapros-bounce@xxxxxxxxxxxxx
>> [mailto:isapros-bounce@xxxxxxxxxxxxx]
>> On Behalf Of Jim Harrison
>> Sent: Tuesday, July 25, 2006 2:19 PM
>> To: isapros@xxxxxxxxxxxxx
>> Subject: [isapros] Re: Port Scan
>>
>> Ask Tony for the BlockAttacker script.
>> I'm sure he's still trying to support it.
>> :-p
>>
>> Tom has it right; you can generally ignore them, since
damn few ISPs
>> even care.
>>
>> -------------------------------------------------------
>> Jim Harrison
>> MCP(NT4, W2K), A+, Network+, PCG
>> http://isaserver.org/Jim_Harrison/
>> http://isatools.org
>> Read the help / books / articles!
>> -------------------------------------------------------
>>
>>
>> -----Original Message-----
>> From: isapros-bounce@xxxxxxxxxxxxx
>> [mailto:isapros-bounce@xxxxxxxxxxxxx]
>> On Behalf Of Amy Babinchak
>> Sent: Tuesday, July 25, 2006 10:21
>> To: isapros@xxxxxxxxxxxxx
>> Subject: [isapros] Port Scan
>>
>> What should I do about a port scan that just won't go
away? I've got
>> two IP addresses port scanning my server around the clock.
An email to
>> the owner bounced back, unknown email address.
>>
>> Is there anything to be done?
>>
>>
>> Amy
>>
>>
>>
>>
>> All mail to and from this domain is GFI-scanned.
>>
>>
>>
>>
>> All mail to and from this domain is GFI-scanned.
>>
>>
>>
>>
>
>
>
>
> All mail to and from this domain is GFI-scanned.
>
>
>
>
All mail to and from this domain is GFI-scanned.
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