Hey Chuck,

Our daily CDR's are usually within a certain file size. If you use
Outlook, you could create a rule to alert you if your CDR size is above
a certain file size. This will also alert you of excessively busy days,
so you can see what caused it in your business.

Cheers,

Doug

-----Original Message-----
From: Chuck Mariotti [mailto:[EMAIL PROTECTED] 
Sent: November-11-08 6:43 PM
To: Chuck Mariotti; Simon P. Ditner; [email protected]
Subject: RE: [on-asterisk] SIP hack attempts

I also made some recommendations to Unlimitel, but maybe this should be
shared with providers as to what would have allowed me to catch this
issue:

I know this is likely a lot of work, but... it would be nice to have the
daily totals in the body of the email and subject. I rarely open my
email attachment to see the minutes used for a day, but if there was a
dollar amount or # of minutes in the subject, it would make it easier to
scan with the eyeball. I would have missed our recent hack completely if
I didn't get returned calls complaining... which made me check my CDR in
Asterisk, which made me look the next day in your report. It also
happened on a Friday night (I'm sure on purpose) so I wouldn't have even
attempted to look until Monday.

I know that's a lot more horsepower needed than just attaching a text
file. But I know it would be helpful to me.

As well, could be useful to set an alert on DID for minutes used in a
day... I think that's asking too much though.

Regards,

Chuck

-----Original Message-----
From: Chuck Mariotti [mailto:[EMAIL PROTECTED] 
Sent: Tuesday, November 11, 2008 6:40 PM
To: Simon P. Ditner; [email protected]
Subject: RE: [on-asterisk] SIP hack attempts

Simon, I ran into and was a victim of such an attack back in mid-august.
I emailed unlimitel and this is the recommendations that Stephen had:


Dear Customer,
We're seeing a lot more hacking activities lately and here's a short
list to do on your server to help keep it secure:
1- Change all your default passwords on the server (root, admin, maint).
Never use easy to remember passwords like 1234,...
2- Never use passwords like 1234 for your any extensions on your server.
There's a lot of hackers out there just scanning your Asterisk server to
detect extensions (200 to 299 mostly) with easy passwords like 1234.
3- Block access to your server and just leave the RTP, SIP and IAX2
opened. Just leave the SSH and WEB access opened to your static IP from
the office. You can do this by using the iptables from Linux on your
Asterisk server.
4- Monitor your network and if you see some activities scanning your
server, keep note of the source IP address and block it completely from
your server.
Hope this few tips can help you keep your server more secure and avoid
big telephone bills.
Stephan Monette
Unlimitel Inc.


-----Original Message-----
From: Simon P. Ditner [mailto:[EMAIL PROTECTED] 
Sent: Tuesday, November 11, 2008 6:00 PM
To: [email protected]
Subject: Re: [on-asterisk] SIP hack attempts

Not a single reply?

It's very easy to disregard this message, but I think this is something 
VERY IMPORTANT that we should be talking about much more -- especially 
for those deploying systems for remote workers over a public network. 
There is a huge opportunity for toll fraud, voip spam, and such as this 
market segment continues to grow.

Lability becomes an issue too -- who's responsible when someone is 
defrauded via your phone system? The phone companies have a record of
you 
calling so-and-so; can you prove you didn't?

These are the sort of scans I've been spotting hitting some of my
systems 
the past week, trying to brute force. You'll see incremental scans like:

[Nov  5 19:58:30] NOTICE[19408] chan_sip.c: Registration from
'"0"<sip:[EMAIL PROTECTED]>' failed for 'EE.FF.GG.HH' - No matching peer
found
...
[Nov  5 20:20:21] NOTICE[19408] chan_sip.c: Registration from
'"1000"<sip:[EMAIL PROTECTED]>' failed for 'EE.FF.GG.HH' - Wrong password
...

We were discussing this around the office, particularly how sipvicious
(http://sipvicious.org) works, and it was noted that you can find active
SIP accounts easily, and then start a brute force against a known active
account.

I poked my head into #asterisk-dev, and asked if there were a feature in
the works to automatically disable accounts after a number of bad auth
attempts. It's been discussed, but so far no code.

There are however some easy things you can do that are common across 
running any service on the internet.

Inside of asterisk, you can cut down on your exposure by only allowing 
particular SIP accounts to be registered from remotely by putting 
deny-based ACL's on the other accounts, listing your local subnets as 
permissable:

sip.conf
[somepeer]
type=peer
deny=0.0.0.0/0.0.0.0
permit=192.168.0.0/255.255.255.0

You can also create automatic blacklisting of IP addresses that attempt 
too many SIP authentications per interval, such as this SSH example:

   http://www.mattiasholm.com/node/6

Thoughts? What are other people doing to protect their exposure?

re,
spd

On Mon, 10 Nov 2008, Andre Courchesne - Consultant wrote:

> Hi,
>
>  Just to let you know that I see a proliferation is SIP hack attempts.
Twice 
> today I happened to be logged in servers where I saw SIP discovery
from IP 
> 212.12.148.109 and on the other server that same IP had actually
gained 
> controlled of a SIP account (which was created with a weak secret by
the 
> administrator).
>
>  The call pattern indicated that calls were made by a dialer of some
sort 
> and the SIP packets were originating from an Asterisk server.
>
>  So be carefull about your server that you have to let unprotected on
an 
> internet segment.
>
> Andre
>
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