I just wanted to give you a quick reminder that SIP scanning remains quite popular on the Internet. These probes can lead to compromise and fraud against your VoIP systems. Make sure you do not have VoIP systems exposed to the Internet without proper controls. If you review your logs on the Internet perimeter, SIP scans will look similar to this:

This was captured from the HITME using HoneyPoint Personal Edition.

2013-09-30 17:02:18 – HoneyPoint received a probe from 207.127.61.156 on port 23

Input: OPTIONS sip:nm SIP/2.0

Via: SIP/2.0/TCP nm;branch=foo

From: <sip:nm@nm>;tag=root

To: <sip:nm2@nm2>

Call-ID: 50000

CSeq: 42 OPTIONS

Max-Forwards: 70

Content-Length: 0

Contact: <sip:nm@nm>

Accept: application/sdp

Keep an inventory of your VoIP exposures. They remain a high area of interest for attackers.