PH_Rule_Perf_306
Enabled
Detects that Hyper-V page fault rate has reached a warning level. Page fault rate is the pace at which pages are read in and out of disk to resolve hard page faults
7
Performance
Impact
Impact consists of techniques that adversaries use to disrupt availability or compromise integrity by manipulating business and operational processes. Techniques used for impact can include destroying or tampering with data. In some cases, business processes can look fine, but may have been altered to benefit the adversaries’ goals. These techniques might be used by adversaries to follow through on their end goal or to provide cover for a confidentiality breach.
https://attack.mitre.org/tactics/TA0040T1499.001
Endpoint Denial of Service: OS Exhaustion Flood
Adversaries may target the operating system (OS) for a DoS attack, since the (OS) is responsible for managing the finite resources on a system. These attacks do not need to exhaust the actual resources on a system since they can simply exhaust the limits that an OS self-imposes to prevent the entire system from being overwhelmed by excessive demands on its capacity.
https://attack.mitre.org/techniques/T1499/001Virtualization
Microsoft HyperV via OMI
Correlation
Identify the process that is consuming high memory, which may lead to why the server is page faulting.
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.
PageFaultWarn
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
eventType = "PH_DEV_MON_HYPERV_MEM_OVERALL"
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
hostName,hostIpAddr
This is most typically a numerical constraint that defines when the rule should trigger an incident
AVG(pageFaultsPersec) > DeviceToCMDBAttr(hostIpAddr,HyperVPageFaultWarn) AND
AVG(pageFaultsPersec) <= DeviceToCMDBAttr(hostIpAddr,HyperVPageFaultCrit) AND
COUNT(*) >= 2
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
hostIpAddr = PageFaultWarn.hostIpAddr,
hostName = PageFaultWarn.hostName,
pageFaultsPersec = PageFaultWarn.AVG(pageFaultsPersec)