- Downloaded shareware software.
- Other modes of online communications, such as instant messaging software.
- Pirated software.
- Via email attachments.
What a virus does:
- Affect specific software.
- Destroy/damage a hard-drive and or other hardware.
- Corrupt data.
- Corrupt software .
- Overwrite data.
- Spread like a human based virus exponentially.
Some common types of known virus:
- Memory: attach's itself to the memory then infects the computer.
- Non-Memory: spreads/attacks when certain applications/utilities are ran.
- Polymorphic: once attached, adapt and modify their code, often contains more than one variant of a virus.
- Stealth: usually attach's itself to certain files, sometimes remains inactive for a certain time, then springs to life and rapidly corrupts all data.
Firewalls:
Taken from the term and use of a firewall that sits between the dashboard and bulkhead of a motor vehicle. A firewall in a information technology environment is considered a first line of defence between the user and the internet.
Can either be a security software program or a hardware device that prevents unauthorized access to a stand alone computer, or a network, by blocking or restricting ports.
Types of firewall:
- Hardware based and usually specific to wide area networks, incorporated in a server or connected to a server.
- Router based, incorporated hardware firewall in a router and used in either local area networks or wide area networks.
- Software based and most commonly used, also known as a personal firewall.
Common defence protocols employed:
- Application Gateway: applies certain security protocols to types of software, for example when using a File Transfer Protocol when uploading specific information to web pages.
- Circuit Level Gateway: provides security in the Transfer Control Protocol between computers, for example when exchanging information between servers, browsing the internet etc.
- Packet Filter: Reads all packets of information(binary code)to and from a computer/network, quite often a preset protocol.
- Proxy Server: Intercepts all messages to and from a computer/network and often hides the exact network addresses.
Anti-Malware:
Commonly referred to as either Adware, Malware, Spyware and or Trojans, the aforementioned are becoming an increasing threat online and quite often install unwanted programs/malicious software and hidden harvesters of both personal and factual use online etc.
Many computer users quite often do not realise when these programs have been secretly installed on their computer and or network, their internet browser and or the computer hijacked.
Common symptoms:
- Computer hangs up and or slows down.
- Backdoor infection such as a keylogger.
- Default search engine or other internet settings changed.
- Default homepage is changed (usually to a different page full of more spyware and or a adult themed type page).
- Different and or new tools added to the browser tool bar, e.g. a unwanted search tool.
- Rogue applications installed.
