alert icmp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Powershell/PowHeartBeat CnC Checkin - ICMP"; dsize:32; itype:8; content:"|3b 1d 41 1d|"; startswith; fast_pattern; content:"abcdefghijklmnopqrstuvwxyz"; distance:2; reference:url,www.welivesecurity.com/2022/09/06/worok-big-picture/; classtype:trojan-activity; sid:2038821; rev:1; metadata:attack_target Client_and_Server, created_at 2022_09_13, deployment Perimeter, malware_family PowerShell_PowHeartBeat, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_09_13;)