PH_Rule_SIGMA_2621
Enabled
Detects execution of the binary "wpbbin" which is used as part of the UEFI based persistence method described in the reference section. This rule is adapted from https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_wpbbin_potential_persistence.yml
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/TA0005T1542.001
Pre-OS Boot: System Firmware
Adversaries may modify system firmware to persist on systems.The BIOS (Basic Input/Output System) and The Unified Extensible Firmware Interface (UEFI) or Extensible Firmware Interface (EFI) are examples of system firmware that operate as the software interface between the operating system and hardware of a computer. System firmware like BIOS and (U)EFI underly the functionality of a computer and may be modified by an adversary to perform or assist in malicious activity.
https://attack.mitre.org/techniques/T1542/001Server
Windows Sysmon via FortiSIEM Agent
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.
Filter
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="Win-Sysmon-1-Create-Process" AND procName="C:\\Windows\\System32\\wpbbin.exe"
This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID
hostName,procName
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
hostName = Filter.hostName,
procName = Filter.procName