PH_Rule_Flow_209
Enabled
Detects a large outbound transfer (larger than 2GB in 10 minutes) from an internal host to an external destination
8
Security
Exfiltration
Exfiltration consists of techniques that adversaries may use to steal data from your network. Once they’ve collected data, adversaries often package it to avoid detection while removing it. This can include compression and encryption. Techniques for getting data out of a target network typically include transferring it over their command and control channel or an alternate channel and may also include putting size limits on the transmission.
https://attack.mitre.org/tactics/TA0010T1048.001
Exfiltration Over Alternative Protocol: Exfiltration Over Symmetric Encrypted Non-C2 Protocol
Adversaries may steal data by exfiltrating it over a symmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.
https://attack.mitre.org/techniques/T1048/001Network
FortiGate via Syslog or Netflow,Checkpoint via Syslog or Netflow, Palo Alto via Syslog or Netflow
Correlation
No remediation guidance specified
If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.
600 seconds
If the following defined pattern/s occur within a 600 second time window.
LargeXfer
This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.
This is the query logic that matches incoming events
srcIpAddr IN (Group@PH_SYS_NETWORK_ENTERPRISE_INTERNAL_NET) AND destIpAddr NOT IN (Group@PH_SYS_NETWORK_ENTERPRISE_INTERNAL_NET) AND reptDevIpAddr IN (Group@PH_SYS_DEVICE_FIREWALL) AND eventType IN (Group@PH_SYS_EVENT_PermitNetTraffic, Group@PH_SYS_EVENT_NetflowTraffic, Group@PH_SYS_EVENT_BiNetflowTraffic)
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
srcIpAddr,destIpAddr,destGeoOrg
This is most typically a numerical constraint that defines when the rule should trigger an incident
SUM(sentBytes64) >= 2000000000
This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.
The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern
srcIpAddr = LargeXfer.srcIpAddr,
destIpAddr = LargeXfer.destIpAddr,
destGeoOrg = LargeXfer.destGeoOrg,
sentBytes64 = LargeXfer.SUM(sentBytes64)