1. Computer Security coursework 3 (part 2) Dr Alexei Vernitski

2. Aims of the coursework Learn more about: – Computer viruses – Files and file systems – Interpreted programming languages, in comparison with compiled programming languages All this is useful not only for understanding computer security, but for any career in information technology

3. Assignment Write a ‘virus’ in Python, namely, a program doing the following: 1.find a file called target.py in the same folder where the program is 2.copy some of its code into the beginning of target.py, thus appending the new code to the existing code in target.py – the code copied should be exactly the code performing the steps 1 and 2 above – Your code should be based on my file sample.py in the sense that it should contain and execute correctly all the original code in sample.py and in addition to this, also should contain ‘virus’ code

4. sample.py You virus code should be appended to the code in the file sample.py which you can find on the module’s web site. Note that the university computers may restrict you from downloading *.py files; this is why I temporarily rename samply.py to sample.py.txt – please rename it back to sample.py

5. What to submit? Submit a ZIP file containing two files: 1.A Python file for Part 1 of Coursework 3 2.A Python file for Part 2 of Coursework 3 Please submit one file, and please submit a ZIP file, it makes opening your assignment easier for me Please include your name and registration number as a comment in your Python code, it makes entering marks easier for me

6. How shall I mark your code? I shall produce a Python file target.py with some code in it and copy it to the folder with your submission I shall look at your code to check that the original code in sample.py is still there; then I shall run your code and see if it does what the original code in sample.py is supposed to do Then I shall look at the changed code in target.py and check that the complete ‘virus’ code has been appended to the original code of target.py in a way which allows target.py to be executed. I may run target.py to see if it still works. If all works correctly, you get 100%. If something does not work, I shall look at the code and allocate some partial marks according to the marking procedure above.

7. Programming I attempted the coursework and wrote my solution in Python – My complete ‘virus’ code contains 9 lines – It took me approximately 20 minutes to write it – You may need up to 1 hour to complete the assignment if you need to learn how to list files in Python, how to get the name of the Python file being executed, etc.

8. Labs Before the submission date of each piece of coursework, we shall have a lab on Monday The purpose of the lab is: – to help you to write your code, in case you have any difficulties – to give you an opportunity to demonstrate your code to me

9. No collaboration This is an individual assignment I shall look for signs of collaboration and plagiarism