An attacker traced out and found the kind of websites a target company/individual is frequently surfing and tested those particular websites to identify any possible vulnerabilities. When the attacker detected vulnerabilities in the website, the attacker started injecting malicious script/code into the web application that can redirect the webpage and download the malware onto the victim's machine. After infecting the vulnerable web application, the attacker waited for the victim to access the infected web application.
Identify the type of attack performed by the attacker.