Common e-security threats
There are a number of e-security threats to be aware of and address. These include:
Adware
Adware is commercial software that delivers targeted advertising to users’ computers without consent. This software may track usage or surfing habits to ensure the advertisements are appropriately targeted for different users. Computers with adware may have a slow boot time or internet response, frequent system program crashes and/or a changed home page. Adware is sometimes offered in exchange for ‘free’ services, such as music downloads.
Malware
An abbreviation for ‘malicious software’, malware is a piece of software that can be unintentionally downloaded and installed without users’ knowledge. Once operational, it can infect a computer with viruses, steal personal information and use the computer to send spam and commit fraud. Information about online scams and identity fraud are covered in detail in the Protecting personal information Common cybersafety issue.
Scams and fraud
The information gathered from adware, malware and spyware can be used for targeted scams or identity fraud. Online scams and fraud are covered in detail in the Protecting personal information Common cybersafety issue.
Spyware
Spyware software is sometimes unintentionally downloaded from the internet with legitimate program downloads. It will install itself in the background, often without users’ knowledge, and is designed to monitor users’ surfing habits. Spyware distributors may pass the information gathered to third parties who may use it to target advertising for products or services or it can be used in targeted online scams or identity fraud. Online scams and identity fraud are covered in detail in the Protecting personal information Common cybersafety issue.
The following signs may indicate that spyware is on a computer:
- the web browser opens on a different homepage
- the computer is slower than normal
- random error messages appear
- new toolbars and icons have been installed.
Trojan
A trojan is a type of malware disguised as a useful piece of software that really has a malicious intent; for example, it may present as a free screensaver or game. Trojans are used to gain unauthorised access to the computer. For example, a trojan infection can result in the logging of key strokes on a keyboard and can record usernames, passwords and sensitive personal information that is sent back to the controller.
Virus
A virus is a piece of computer code that may be introduced to a computer by an insecure internet connection, an infected website, a device plugged into the computer, or an email or downloaded file, without the knowledge of the user. The purpose of a virus is to corrupt the computer system or destroy data. Computer viruses can be hidden in documents or files and transmitted as email attachments, embedded in computer games, video clips or photos.
The most common symptoms that a computer has been infected by a virus include:
- files and data have been deleted
- the computer takes longer to load programs or applications
- the computer takes longer to boot, continually restarts or does not start at all
- items and images on the screen are distorted and unusual images and text appear
- excessive network activity (lights blinking excessively on modem)
- the web browser opens on a different homepage
- internet pages are slow to load
- the hard disk may be inaccessible or appear to be working harder than normal
- disk space and filenames change
- frequent system or program crashes.
This is not an exhaustive list and these symptoms may occur for reasons other than a virus infection. Seek advice from a computer professional if you suspect your computer may have become infected by a virus.
Worm
A worm is a self-replicating program that can spread without user intervention. Worms are designed to further infect computers with other types of malicious software, such as programs that send spam. A worm can spread by sending itself to all the contacts in an email program's address book, or via a security flaw in a program or in the computer’s operating system.
Stay Smart Online
The Australian Government’s site set up to provide online users with practical tips and advice on e-security. Home users can also access information on the latest e-security threats through a free alert service.