alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET RETIRED Shuckworm Backdoor Screenshot Upload Attempt"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/index.php"; bsize:10; http.header_names; content:!"Referer"; content:!"User-Agent"; http.request_body; content:"izTpDFBfSol="; fast_pattern; content:"img="; reference:md5,4a967bbd28f5738185cf46a245918f77; reference:url,symantec-enterprise-blogs.security.com/blogs/threat-intelligence/russia-ukraine-shuckworm; classtype:trojan-activity; sid:2038571; rev:2; metadata:attack_target Client_and_Server, created_at 2022_08_19, deployment Perimeter, former_category MALWARE, malware_family Shuckworm, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_09_17, reviewed_at 2024_09_17;)