Which term describes a malicious piece of code or script that is developed using server-side languages and then installed on a target server?

Which term describes a malicious piece of code or script that is developed using server-side languages and then installed on a target server?

• A. Web Shell
• B. Backdoor
• C. Trojan
• D. Rootkit

Answer: (A)

A web shell is a malicious script written in a server-side language (such as PHP, ASP.NET, Python, or Ruby) that an attacker uploads to a compromised web server to gain remote control of that server through a web interface. Because it runs on the server, it operates with the server’s permissions and can execute commands, read or modify files, upload or download data, and create new accounts, all accessible by a web request. This makes it a persistent and convenient tool for an attacker to maintain access and move laterally within the target environment. The other terms describe different attack concepts. A Trojan is software that pretends to be legitimate to entice users into running it, while a rootkit hides their presence and maintains stealthy access at a low level. A backdoor is any hidden method to bypass normal authentication or access controls; a web shell is a specific kind of backdoor that is delivered as a server-side script and used via the web to control the server.

A web shell is a malicious script written in a server-side language (such as PHP, ASP.NET, Python, or Ruby) that an attacker uploads to a compromised web server to gain remote control of that server through a web interface. Because it runs on the server, it operates with the server’s permissions and can execute commands, read or modify files, upload or download data, and create new accounts, all accessible by a web request. This makes it a persistent and convenient tool for an attacker to maintain access and move laterally within the target environment.

The other terms describe different attack concepts. A Trojan is software that pretends to be legitimate to entice users into running it, while a rootkit hides their presence and maintains stealthy access at a low level. A backdoor is any hidden method to bypass normal authentication or access controls; a web shell is a specific kind of backdoor that is delivered as a server-side script and used via the web to control the server.