[Zope] msadc exploit?

I received multiple error reports from my Zope server tonight, about an object not found at http://NETSERVER:8080/msadc/..Á%8s../..Á%8s../..Á%8s../winnt/system32/cmd.exe being called from ip address: 61.156.8.19 This is very odd as my web server is at port 80, and mapped by NAT to 8080. I presume that this is some sort of attack on my webserver - what are they trying to exploit? -- Graham Chiu