Two-page essay of understanding OS, Please do option 1 of the essay prompt with PNG

Trojan Horse
Trojan Horse can be defined as a program which performs some maliciousness secretly along with the visible actions. Code of such programs are written deliberately and rest of them are the outcomes of legitimate programs which are affected with the virus (Bernaschi, Massimo, Emanuele Gabrielli, and Luigi V. Mancini.). The long search parts are dangerous for that trojan horses which includes the current directory in the URL path. If the program with the same name as given to the legitimate program is placed on the URL path, then a non-technical user can run the wrong program unknowingly. Another type of the Trojan horse is login emulator. In this the program records the account user name and password of the user and prompts wrong password message and the system is logged off. When the user tries to enter the details again then the login is successful and there are no symptoms of stealing (Deng, Fu-Guo, et al.).
The solution to Trojan horse is to have print command for the system on logout. This print will help to get the usage statistics and will ask user to type any...