alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Bitter APT Related Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/vis.php?st="; fast_pattern; http.user_agent; content:"Windows Installer"; bsize:17; reference:md5,6e4b4eb701f3410ebfb5925db32b25dc; reference:url,twitter.com/k3yp0d/status/1527656133837594624; classtype:trojan-activity; sid:2036646; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_05_20, deployment Perimeter, malware_family Bitter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_05_20;)