Event 5025: The Windows Firewall Service has been stopped.

Adversaries may stop or disable services on a system to render those services unavailable to legitimate users. Stopping critical services or processes can inhibit or stop response to an incident or aid in the adversary's overall objectives to cause damage to the environment.(Citation: Talos Olympic Destroyer 2018)(Citation: Novetta Blockbuster) Adversaries may accomplish this by disabling individual services of high importance to an organization, such as <code>MSExchangeIS</code>, which will make Exchange content inaccessible.(Citation: Novetta Blockbuster) In some cases, adversaries may stop or disable many or all services to render systems unusable.(Citation: Talos Olympic Destroyer 2018) Services or processes may not allow for modification of their data stores while running. Adversaries may stop services or processes in order to conduct [Data Destruction](https://attack.mitre.org/techniques/T1485) or [Data Encrypted for Impact](https://attack.mitre.org/techniques/T1486) on the data stores of services like Exchange and SQL Server.(Citation: SecureWorks WannaCry Analysis)

Adversaries may disable or modify system firewalls in order to bypass controls limiting network usage. Changes could be disabling the entire mechanism as well as adding, deleting, or modifying particular rules. This can be done numerous ways depending on the operating system, including via command-line, editing Windows Registry keys, and Windows Control Panel. Modifying or disabling a system firewall may enable adversary C2 communications, lateral movement, and/or data exfiltration that would otherwise not be allowed. For example, adversaries may add a new firewall rule for a well-known protocol (such as RDP) using a non-traditional and potentially less securitized port (i.e. [Non-Standard Port](https://attack.mitre.org/techniques/T1571)).(Citation: change_rdp_port_conti) Adversaries may also modify host networking settings that indirectly manipulate system firewalls, such as interface bandwidth or network connection request thresholds.(Citation: Huntress BlackCat) Settings related to enabling abuse of various [Remote Services](https://attack.mitre.org/techniques/T1021) may also indirectly modify firewall rules.