Malicious Code
- Define the term malware.
- Describe what malware is and how it can be protected against.
- Describe the following forms of malware:
- computer virus
- trojan
- spyware
Malware
- Malware covers any kind of hostile or intrusive software.
- Malware (malicious code) is software written to:
- cause damage and disrupt the functionality of a computer system
- steal data
- Usually installed without the users knowledge.
Viruses
- Computer code that is hidden within another program.
- Virus code is only run when the host program is executed.
- Can delete data or change system files so that data is corrupted.
- Some viruses fill up the hard drive so that the computer runs very slowly or becomes unresponsive.
Viruses
- Viruses can replicate themselves and insert themselves into other programs.
- They spread through:
- attachments to emails
- files, programs, games, etc. downloaded from web sites or portable storage (USB sticks, CDs)
Viruses
- Avoid opening emails and attachments from sources you do not know or trust.
- Avoid downloading from sites you do not trust.
- Avoid using unknown portable storage devices.
Trojans
- Programs that users are tricked into installing, believing they are legitimate and useful.
- Often freeware/shareware programs with the malicious code hidden inside the program.
- Will activate once the program is installed.
Trojans
- Some Trojans are just annoying, changing the desktop layout or showing pop-up adverts.
- Other Trojans are dangerous,
- they can delete files,
- send screenshots to a third party
- log and send keystrokes to a third party
- Important to download files from site that you know and trust.
Spyware
- Malware that is packaged with other software, such as free software that a user downloads.
- Spyware monitors information about the user and sends it back to the originator.
- Most well known spyware are keyloggers that monitor usernames, passwords and other sensitive data.
- You can get anti-spyware programs and most virus checker software will also look for spyware.
- Avoid downloading software from unknown/untrusted sites.
Anti-Malware Software
- Designed to detect and remove malware.
- Needs to be regularly updated because malware is constantly being changed and improved.
- As information about new malware becomes available the anti-virus companies update their software to improve the protection for their customers.
Anti-Malware Software
Provides system protection by:
- performing real-time scans of incoming network traffic to detect infected files,
- performs periodic (daily/weekly) scans of the whole system looking for malware that is already installed,
- quarantining the infected files to prevent them running and allowing the user to delete the files.
Questions
- Match the type of malware to the description of how it is spread.
1) Virus 2) Spyware 3) Trojan
A) Malware disguised as legitimate software.
B) Malware that comes packaged with other software.
C) Malware that is spread through infected files.
- Explain how anti-malware software helps to protect a system.
Answers
Virus - malware that is spread through infected files.
Spyware - malware that comes packaged with other software.
Trojan - malware disguised as legitimate software.
- Match the type of malware to the description of how it is spread.
1) Virus 2) Spyware 3) Trojan
A) Malware disguised as legitimate software.
B) Malware that comes packaged with other software.
C) Malware that is spread through infected files.
Answers
- Performing real-time scans of incoming network traffic to detect infected files,
- Performs periodic (daily/weekly) scans of the whole system looking for malware that is already installed,
- Quarantining the infected files to prevent them running and allowing the user to delete the files.
- Explain how anti-malware software helps to protect a system.