--engine-analysis warning for flow on an icmp request rule
using latest git master at the moment of this report -
5.0.0-dev (3a91244 2019-07-22)
I have the following warning on
== Sid: 2027763 == alert icmp any any -> any any (msg:"ET TROJAN Possible ICMP Backdoor Tunnel Command - whoami"; itype:8; icode:0; content:"whoami"; depth:6; nocase; metadata: former_category TROJAN; reference:url,www.hackingarticles.in/command-and-control-tunnelling-via-icmp; classtype:trojan-activity; sid:2027763; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, deployment Perimeter, signature_severity Major, created_at 2019_07_29, performance_impact Moderate, updated_at 2019_07_29;) Rule matches on packets. Rule contains 1 content options, 0 http content options, 0 pcre options, and 0 pcre options with http modifiers. Fast Pattern "whoami" on "payload" buffer. Warning: Rule is inspecting both the request and the response.
where the rules is inspecting itype:8; icode:0;