alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE MSIL/Crimson Receiving Command (ping) M1"; flow:established,from_server; content:"clping=Ping"; offset:5; byte_jump:4,0,little,from_beginning,post_offset 4; isdataat:!2,relative; reference:md5,94d29dded4dfd920fc4153f18e82fc6c; reference:md5,40c9031ee6bbf2b2306420e9330727a6; classtype:trojan-activity; sid:2035904; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2016_02_17, deployment Perimeter, malware_family Crimson, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)