alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/images/L._SX2_.jpg"; bsize:19; http.host; content:"static.mhysl.org"; bsize:24; fast_pattern; http.user_agent; content:"Mozilla/5.0|20|(Windows|20|NT|20|6.1|3b 20|WOW64|3b 20|Trident/7.0|3b 20|rv|3a|11.0)|20|like|20|Gecko"; bsize:68; http.header_names; content:!"Referer"; reference:url,www.ptsecurity.com/ww-en/analytics/pt-esc-threat-intelligence/new-apt-group-chamelgang/; classtype:trojan-activity; sid:2034082; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_10_01, deployment Perimeter, deployment SSLDecrypt, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2021_10_01, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)