alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Possible Mask C2 Traffic"; flow:established,to_server; http.uri; content:".cgi?Group="; nocase; content:"&Ver="; nocase; content:"&Inst"; nocase; content:"&Ask="; nocase; content:"&Bn="; nocase; reference:url,www.securelist.com/en/downloads/vlpdfs/unveilingthemask_v1.0.pdf; classtype:command-and-control; sid:2018105; rev:3; metadata:created_at 2014_02_11, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_27;)