Consultas para la tabla NetworkSessions

Para obtener información sobre el uso de estas consultas en Azure Portal, consulte tutorial de Log Analytics. Para obtener la API REST, consulte Consulta.

Obtención del tráfico a puertos no estándar

Esta consulta identifica las direcciones IP de origen que envían solicitudes de conexión a través de varios puertos. Esto podría ser una indicación de los intentos de adversario de enumerar los servicios disponibles. Referencias: Examen del servicio de red MITRE (T1046)

// This query identifies source IP addresses sending connection requests over multiple ports.
// This could be an indication of adversary attempts to list available services.
// References: MITRE Network Service Scanning (T1046)
let threshold=5;
// Used to filter commonly used ports in your org
let commonPorts=dynamic([443, 53, 389, 80, 0, 880, 8888, 8080]);
NetworkSessions
 | where isnotempty(DstPortNumber) and not(ipv4_is_private(DstIpAddr) ) 
 // filter out IANA ephemeral or negotiated ports as per https://en.wikipedia.org/wiki/Ephemeral_port
 | where DstPortNumber !between (toint(49512) .. toint(65535)) 
     and DstPortNumber !in (commonPorts)
 | where EventResult == "Failure" 
 | summarize PortCount=dcount(DstPortNumber) by SrcIpAddr, bin(TimeGenerated, 2m)
 | where PortCount > threshold

Tráfico de gran volumen a dominios poco comunes

Esta consulta identifica los dominios que reciben una cantidad inusual de volumen de datos. Esto podría ser una indicación de intentos de adversario de robar y filtrar datos.

// This query identifies domains receiving uncommon about of data volume.
// This could be an indication of adversary attempts to steal and exfiltrate data.
let isInternal = (url_hostname:string){url_hostname endswith ".local" or url_hostname endswith ".lan" or url_hostname endswith ".home"};
    // used to exclude internal traffic
let top1M =  (externaldata (Position:int, Domain:string) [@"http://s3-us-west-1.amazonaws.com/umbrella-static/top-1m.csv.zip"]  with (format="csv", zipPattern="*.csv"));
    // fetch the alexa top 1M domains
let top2ndLevelDomain=top1M
    | extend Domain = tolower(extract("([^.]*).{0,7}$", 1, Domain)) 
    | distinct Domain;
let rareDomainTraffic = NetworkSessions
    | where isnotempty(UrlHostname) and not(isInternal(UrlHostname))
    | extend SndLevelDomain=tolower(extract("([^.]*).{0,7}$", 1, UrlHostname))
    | where SndLevelDomain !in (top2ndLevelDomain)
    | summarize BytesSent=sum(SrcBytes) by SndLevelDomain, UrlHostname;
rareDomainTraffic | summarize TotalBytes=sum(BytesSent) by SndLevelDomain
| join kind=innerunique
    rareDomainTraffic
        on SndLevelDomain
| sort by TotalBytes desc