strange shared link

Yesterday my wife noticed that in the finder sidebar, under shared, there
was a section marked 'all' and clicking that showed all the machines as
expected, both the macs and the windows machines, and another entry with a
globe icon '' which appear to be a spamming

Did a search through console and various system things looking for a
traceof this, and didn't find any. A restart made it go away (including the
'all' entry that I have never seen).

Anyone any clue what this was?