Determining threat level associated with network activity
View Patent ↗Network devices such as intrusion detection systems, routers, firewalls, servers, and other network devices are monitored to aggregate all event data generated by monitored devices to provide a threat ranking of all network activity. A threat level for a given host is determined by a threat weighting assigned to that host and a threat weighting assigned to that host's netblock. In addition, a vulnerability for a given event is determined by the event's destination threat associated with a vulnerability value indexed by the event's destination and the event's type.
1. A computer-implemented method for determining network security threat level, comprising:
receiving event data in response to identified network event detected by a sensor;
based upon the event data:
determining a source threat value, the source threat value based upon a source threat weight for a source IP address and a first range of IP network addresses of which the source IP address is a member;
determining a destination vulnerability value, the destination vulnerability value based upon the network event in conjunction with a destination IP address, a destination threat weight for the destination IP address, and a threat level value associated with a second range of network IP address of which the destination IP address is a member;
determining an event validity value based upon the source IP address and an event type;
determining event severity value based upon the event type;
calculating an event threat level value based upon the source threat value, the destination vulnerability value, the event validity value, and the event severity value;
calculating a host threat level value based upon a summation of event threat level values for a host over a first time period associated with a number of correlated events for the host in the first time period;
calculating a differential threat level by associating the host threat level value with a second host threat level value based upon a second time period wherein the second time period exceeds the first time period;
generating at least one of: a threat report and a threat presentation based at least on the calculated threat levels; and
outputting the at least one of: threat report and threat presentation.
2. The method of claim 1 ,further comprising the steps of:
comparing the event threat level value to an event alert value; and
generating an alarm when the event threat level value exceeds the event alert value.
3. The method of claim 1 , further comprising the steps of:
comparing the host threat level value to a host alert value; and
generating an alarm when the host threat level value exceeds the host alert value.
4. The method of claim 1 , further comprising the steps of:
comparing the differential threat level value to a differential alert value; and
generating an alarm when the differential threat level value exceeds the differential alert value.
5. A method for determining network security threat level, comprising:
receiving event data in response to an identified network event detected by a sensor;
determining an event type based upon the event data; and
determining a source threat based upon a source threat weighting assigned to a source for the event type associated with a network block threat weighting for the event type assigned to a host network block of which the host is a member;
determining a destination threat value based upon a destination threat weighting assigned to the destination for the event type associated with a network block threat weighting for the event type assigned to a host network block of which the host is a member;
determining a destination vulnerability by associating the destination threat value with a destination vulnerability value based upon a vulnerability of a destination host for the event type;
determining an event validity based upon the source and the event type;
determining an event severity based upon the event type;
calculating the network security threat based upon the source threat, the destination vulnerability, the event validity, and the event severity;
generating at least one of: a threat report and a threat presentation based at least on the calculated network security threat; and
outputting the at least one of: threat report and threat presentation.
6. A method for determining network security threat level, comprising:
receiving event data in response to an identified network event detected by a sensor;
determining an event type based upon the event data;
determining a source threat based upon a source threat weighting assigned to a source for the event type associated with a network block threat weighting for the event type assigned to a host network block of which the host is a member;
determining a destination threat value based upon a destination threat weighting assigned to the destination for the event type associated with a network block threat weighting for the event type assigned to a host network block of which the host is a member;
determining a destination vulnerability by associating the destination threat value with a destination vulnerability value based upon a vulnerability of a. destination host for the event type;
determining an event validity based upon the source and the event type;
determining an event severity base upon the event type;
calculating an event threat based upon the source threat, the destination vulnerability, the event validity, and the event severity;
calculating a compound host threat by associating a plurality of event threats over a time period with a number of correlated events in the time period;
generating at least one of: a threat report and a threat presentation based at least on the calculated threat levels; and
outputting the at least one of: threat report and threat presentation.
7. A method for determining network security threat level, comprising:
receiving event data in response to an identified network event detected by a sensor;
determining an event type based upon the event data;
determining a source threat based upon a source threat weighting assigned to a source for the event type associated with a network block threat weighting for the event type assigned to a host network block of which the host is a member;
determining a destination threat value based upon a destination threat weighting assigned to the destination for the event type associated with a network block threat weighting for the event type assigned to a host network block of which the host is a member;
determining a destination vulnerability by associating the destination threat value with a destination vulnerability value based upon a vulnerability of a destination host for the event type;
determining an event validity based upon the source and the event type;
determining an event severity base upon the event type;
determining an event threat based upon the source threat, the destination vulnerability, the event validity, and the event severity;
determining a first compound host threat value by associating a first plurality of event threats over a first time period with a first frequency number of correlated events in the first time period;
determining a second compound host threat value by associating a second plurality of event threats over a second time period greater than the first time period with a second frequency number of correlated events in the second time period;
determining a differential threat level by associating the first compound host threat value with the second host threat value;
generating at least one of: a threat report and a threat presentation based at least on the calculated threat levels; and
outputting the at least one of: threat report and threat presentation.
8. A method for determining network security threat level, comprising:
receiving event data in response to an identified network event detected by a sensor;
determining an event type based upon the event data;
based upon the event data, perform the following steps:
determining a first host frequency threat level value by summing event threat level values for a host over a first time period dividing by the number of correlated events for the host in the first time period;
determining a second host frequency threat level value by summing event threat level values for the host over a second time period greater than the first time period and associated with the number of correlated events for the host in the second time period;
determining a differential threat level numerator by multiplication of the first host frequency threat level value by the second time period;
determining a differential threat level denominator by multiplying the second host frequency value by the first time period, and
calculating a differential threat level by dividing the differential threat level numerator by the differential threat level denominator;
generating at least one of: a threat report and a threat presentation based at least on the calculated differential threat level; and
outputting the at least one of: threat report and threat presentation.