ET MALWARE OWAReaper C2 File Exfiltration (ews_extensions_debug.json)

alert http [$HOME_NET,$SMTP_SERVERS] any -> any any (
    msg:"ET MALWARE OWAReaper C2 File Exfiltration (ews_extensions_debug.json)";
    flow:established,to_server;
    http.uri;
    content:"/assets/v1_"; fast_pattern;
    pcre:"/^[A-Za-z0-9\x2d\x5f]+$/R";
    http.request_body; strip_whitespace;
    content:"|22|InstalledExtensionsCollection|22 3a|";
    content:"|22|ResponseMessages|22 3a|";
    http.method;
    content:"POST";
    classtype:trojan-activity;
    sid:2071333; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2026_07_28, deployment Perimeter, malware_family OWAReaper, confidence High, signature_severity Major, tag c2, updated_at 2026_07_28, former_sid 2868081, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)