A threat intelligence feed data file has been acquired and stored in the Documents folder...

5.9.188.148 is the IP address linked with http://securityabc.s21sec.com in the above scenario. A threat intelligence feed is a source of data that provides information about current or potential threats and attacks that can affect an organization’s network or system. A threat intelligence feed can include indicators of compromise (IoCs), such as IP addresses, domain names, URLs, hashes, etc., that can be used to detect or prevent malicious activities. To analyze the threat intelligence feed data file and determine the IP address linked with http://securityabc.s21sec.com, one has to follow these steps:

Navigate to the Documents folder of Attacker-1 machine.

Open Threatfeed.txt file with a text editor.

Search for http://securityabc.s21sec.com in the file.

Observe the IP address associated with the URL.

The IP address associated with the URL is 5.9.188.148, which is the IP address linked with http://securityabc.s21sec.com.