alert tcp $EXTERNAL_NET any -> $HOME_NET 139 (msg:"GPL NETBIOS SMB IPC$ share access"; flow:established,to_server; content:"|00|"; depth:1; content:"|FF|SMBu"; within:5; distance:3; byte_test:1,!&,128,6,relative; byte_jump:2,34,little,relative; content:"IPC|24 00|"; distance:2; nocase; flowbits:set,smb.tree.connect.ipc; classtype:protocol-command-decode; sid:2100537; rev:17; metadata:created_at 2010_09_23, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)