According to jotti.org Backdoor.Agent.cnd not detected Backdoor.Agent.cnd http://research.sunbelt-software.com/threatdisplay.aspx?name=Backdoor.Agent.cnd&threatid=205746
It's been stated here numerous times that: 1, no AV detects 100% of all threats. There are tons of examples where NOD32 is one of 2-3 AVs to detect a fast spreading threat (ie. Nuwar). 2, a sample must be analysed in order to tell if it's actually functional and carries out malicious actions. Did you actually send it to samples[at]eset.com? How do you know the NOD32 users are not protected against it by the web scanner? Even though the results from an online scanners would not show the file as detected, the users might be actually protected against it.
Thanks for explanation i am paid NOD32 user and love the product and you right web scanner could be wrong i have even seen web scanner showed NOD32 detected a virus and KAV did not