Terry is managing a web server that runs a PHP-based web service and discovered a large number of php-cgi processes consuming significant CPU. What can Terry infer from this observation?

When a web server is running a PHP-based web service and exhibits a high number of php-cgi processes consuming significant CPU resources, it can suggest several potential issues. In this context, inferring a Denial of Service (DoS) attack is a reasonable conclusion.

A DoS attack aims to overwhelm a service or network with excessive requests, rendering it unable to respond to legitimate traffic. The large number of php-cgi processes indicates an abnormal load, which may stem from malicious users attempting to flood the server with requests in a short timeframe. This sustained high resource usage can lead to degraded performance or a complete shutdown of the web service, effectively denying access to legitimate users.

The other potential issues are important to consider but do not directly correlate with the symptoms described. Unauthorized access typically pertains to breaches where access controls are circumvented but may not necessarily manifest in high CPU usage from php-cgi processes. Similarly, a Trojan attack usually involves unauthorized software that can create backdoors or steal data, while php-cgi injection attacks would also focus on exploiting vulnerabilities in the web application to execute malicious code, rather than solely resulting in high CPU resource consumption. Therefore, the situation described leans most clearly toward a DoS attack due to the noticeable impact on