alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (msg:"ET EXPLOIT Possible WatchGuard CVE-2022-26318 RCE Attempt M3"; flow:established,to_server; http.request_line; content:"POST /agent/login"; startswith; fast_pattern; http.content_len; byte_test:0,>,450,0,string,dec; http.header; content:"Content-Encoding|3a 20|gzip"; http.request_body; content:"|1f 8b|"; startswith; reference:url,attackerkb.com/topics/t8Nrnu99ZE/cve-2022-26318; reference:url,www.greynoise.io/blog/watchguard-cve-2022-26318-rce-detection-iocs-and-prevention-for-defenders; reference:cve,2022-26318; classtype:attempted-admin; sid:2035635; rev:2; metadata:attack_target Networking_Equipment, created_at 2022_03_29, cve CVE_2022_26318, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence Medium, signature_severity Major, tag CISA_KEV, updated_at 2022_03_29;)