On Monday, 2003-06-23 at 01:59 AST, Sean Donelan <sean@donelan.com> wrote:
http://www.lurhq.com/popup_spam.html
"LURHQ Corporation has observed traffic to large blocks of IP addresses on udp port 1026. This traffic started around June 18, 2003 and has been constant since that time. LURHQ analysts have determined that the source of the traffic is spammers who have discovered that the Windows Messenger service listens for connections on port 1026 as well as the more widely-known port 135. Windows Messenger has been a target for spammers since late last year, because it allows anonymous pop-up messages to be displayed on any Windows system running the messenger service. Due to widespread abuse, many ISPs have moved to block inbound traffic on udp port 135. It appears the spammers have adapted, so ISPs are urged to block udp port 1026 inbound as well."
How many ports should ISPs block? People still buy and connect insecure computers to the net.
Good point. In this case, stateless blocking of traffic to 1026/udp will block several per cent of the responses to dns queries (in addition to substantial other legitimate traffic). This is a denial of service for your own customers. Tony Rall