PH_Rule_ADV_18
Enabled
Detects NIPS evasion attempts
7
Security
Defense Evasion
Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics’ techniques are cross-listed here when those techniques include the added benefit of subverting defenses.
https://attack.mitre.org/tactics/TA0005T1211
Exploitation for Defense Evasion
Adversaries may exploit a system or application vulnerability to bypass security features. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code.??Vulnerabilities may exist in defensive security software that can be used to disable or circumvent them.Adversaries may have prior knowledge through reconnaissance that security software exists within an environment or they may perform checks during or shortly after the system is compromised for [Security Software Discovery](https://attack.mitre.org/techniques/T1518/001). The security software will likely be targeted directly for exploitation. There are examples of antivirus software being targeted by persistent threat groups to avoid detection.
https://attack.mitre.org/techniques/T1211Network
FortiGate via Syslog, FortiProxy via Syslog, Checkpoint IPS-1 via LEA/Syslog, PaloAlto PAN-OS via Syslog
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.
300 seconds
If the following defined pattern/s occur within a 300 second time window.
IPSScan
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
reptDevIpAddr IN (Group@PH_SYS_DEVICE_NETWORK_IPS) AND eventType IN (Group@PH_SYS_EVENT_EvasionExploit)
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
srcIpAddr,destIpAddr,eventType,ipsSignatureId
This is most typically a numerical constraint that defines when the rule should trigger an incident
COUNT(*) >= 1
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 = IPSScan.srcIpAddr,
destIpAddr = IPSScan.destIpAddr,
compEventType = IPSScan.eventType,
ipsSignatureId = IPSScan.ipsSignatureId,
incidentCount = IPSScan.COUNT(*)