Query: Suspicious System Shutdown/Reboot execution detected on endpoint
Matching passage: T1529 System Shutdown/Reboot. Tactics: impact. Description: Adversaries may shutdown/reboot systems to interrupt access to, or aid in the destruction of, those systems. Operating systems may contain commands to initiate a shutdown/reboot of a machine or network device. In some cases, these commands may also be used to initiate a shutdown/reboot of a remote computer or network device via [Network Device CLI](https://attack.mitre.org/techniques/T1059/008) (e.g. <code>reload</code>).(Citation: Microsoft Shutdown Oct 2017)(Citation: alert_TA18_106A) They may also include shutdown/reboot of a virtual machine via hypervisor / cloud consoles or command line tools. Shutting down or rebooting systems may disrupt access to computer resources for legitimate users while also impeding incident response/recovery. Adversaries may also use Windows API functions, such as `InitializeSystemShutdownExW` or `ExitWindowsEx`, to force a system to shut down or reboot.(Citation: CrowdStrike Blog)(Citation: Unit42 Agrius 2023) Alternatively, the `NtRaiseHardError`or `ZwRaiseHardError` Windows API functions with the `ResponseOption` parameter set to `OptionShutdownSystem` may deliver a “blue screen of death” (BSOD) to a system.(Citation: SonicWall)(Citation: NtRaiseHardError)(Citation: NotMe-BSOD) In order to leverage these API functions, an adversary may need to acquire `SeShutdownPrivilege` (e.g., via [Access Token Manipulation](https://attack.mitre.org/techniques/T1134)).(Citation: Unit42 Agrius 2023) In some cases, the system may not be able to boot again. Adversaries may attempt to shutdown/reboot a system after impacting it in other ways, such as [Disk Structure Wipe](https://attack.mitre.org/techniques/T1561/002) or [Inhibit System Recovery](https://attack.mitre.org/techniques/T1490), to hasten the intended effects on system availability.(Citation: Talos Nyetya June 2017)(Citation: Talos Olympic Destroyer 2018)
Near-miss passage: T1499.002 Service Exhaustion Flood. Tactics: impact. Description: Adversaries may target the different network services provided by systems to conduct a denial of service (DoS). Adversaries often target the availability of DNS and web services, however others have been targeted as well.(Citation: Arbor AnnualDoSreport Jan 2018) Web server software can be attacked through a variety of means, some of which apply generally while others are specific to the software being used to provide the service. One example of this type of attack is known as a simple HTTP flood, where an adversary sends a large number of HTTP requests to a web server to overwhelm it and/or an application that runs on top of it. This flood relies on raw volume to accomplish the objective, exhausting any of the various resources required by the victim software to provide the service.(Citation: Cloudflare HTTPflood) Another variation, known as a SSL renegotiation attack, takes advantage of a protocol feature in SSL/TLS. The SSL/TLS protocol suite includes mechanisms for the client and server to agree on an encryption algorithm to use for subsequent secure connections. If SSL renegotiation is enabled, a request can be made for renegotiation of the crypto algorithm. In a renegotiation attack, the adversary establishes a SSL/TLS connection and then proceeds to make a series of renegotiation requests. Because the cryptographic renegotiation has a meaningful cost in computation cycles, this can cause an impact to the availability of the service when done in volume.(Citation: Arbor SSLDoS April 2012)