FortiSIEM Rules

Outbreak: Active Directory Privilege Escalation Exploit Detected on Network

Rule ID


Default Status



A Fortinet product has detected an exploit related to CVE-2021-42287 or CVE-2021-42278 on network






Resource Development

Resource Development consists of techniques that involve adversaries creating, purchasing, or compromising/stealing resources that can be used to support targeting. Such resources include infrastructure, accounts, or capabilities. These resources can be leveraged by the adversary to aid in other phases of the adversary lifecycle, such as using purchased domains to support Command and Control, email accounts for phishing as a part of Initial Access, or stealing code signing certificates to help with Defense Evasion.

MITRE ATT&CK® Techniques


Compromise Infrastructure: Domains

Before compromising a victim, adversaries may hijack domains and/or subdomains that can be used during targeting. Domain registration hijacking is the act of changing the registration of a domain name without the permission of the original registrant. An adversary may gain access to an email account for the person listed as the owner of the domain. The adversary can then claim that they forgot their password in order to make changes to the domain registration. Other possibilities include social engineering a domain registration help desk to gain access to an account or taking advantage of renewal process gaps. Subdomain hijacking can also occur when organizations have DNS entries that point to non-existent or de-provisioned resources. In such cases, an adversary may take control of a subdomain to conduct operations with the benefit of the trust associated with that domain.



Data Source

FortiGate via Syslog, FortiProxy via Syslog



Remediation Guidance

Check if the source is patched for the CVE associated with the event. If yes then remove the host from the network and patch immediately. If host is not scanned then determine if the host is running the affected version of the application. If yes then patch immediately, else it is likely a false positive.

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

300 seconds

Trigger Conditions

If the following defined pattern/s occur within a 300 second time window.


SubPattern Definitions

SubPattern Name: ad_priv_escalation

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType IN ("FortiGate-ips-signature-51057","FortiProxy-ips-signature-51057")

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID


Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) >= 1

Incident Attribute Mapping

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