A webshell is a program that executes arbitrary commands on a web server to upload, delete, download files, execute system commands, etc. It is also called a web backdoor.
Uploading a webshell (webshell) to a web server allows remote access to the web server, including the web server’s file system.
Webshells (webshells) are characterized by the fact that users can access a web server through a web browser that acts like a command line interface.
Customers can access remote computers via the World Wide Web using a web browser on any type of system, such as a desktop PC or a cell phone with a web browser, and perform tasks on the remote system.
No command line environment is required on the host or client side.
Webshells (webshells) are sometimes used for remote access Trojans
Webshells can be used with a fairly wide range of programming languages running on the target server, with PHP being the most prominent attack.
Active Server Pages, ASP.NET, Python, Perl, Ruby, and Unix shell scripts are also sometimes used, but not as often because web servers using these languages are not as common.
Vulnerabilities to webshell attacks can be found in content management system (CMS) applications and web server software.
The attacker uses a web shell to issue commands, perform privilege escalation on the web server, upload, delete, download files, execute system commands, etc. on the web server