Gizmo's Freeware Reviews: Best Free Trojan Scanner/Trojan Remover

23 April 2012
by torres-no-tan-magnifico

Introduction

Malware, trojans and threats

Most PCs are now connected to the Internet and networks, making easier the spread of malicious software (malware), which includes trojans (also known as trojan horses), viruses, worms, spyware, adware, rootkits and other malicious or unwanted programs.

Like spyware and adware, trojans can get onto your computer in a number of ways, including from a web browser, via e-mail, or in a bundle with other software downloaded from the Internet. You may also inadvertently transfer malware via a USB flash drive or other portable media. It is possible that you could be forced to reformat your USB flash drive or other portable device in order to eliminate the infection and avoid transferring it to other machines. (After all, you don't want to be the one who infected your network at work because you were bringing in some music to listen to.)

Unlike viruses or worms, trojans do not replicate themselves but they can be just as destructive. On the surface, trojans appear benign and harmless, but once the infected code is run, trojans kick in and perform malicious functions to harm the computer system without the user's knowledge.

For example, waterfalls.scr is a waterfall screen saver as originally claimed by the author, but it can be associated with malware and become a trojan to unload hidden programs and allow unauthorized access to the user's PC.

Some typical examples of threats by trojans are as follows:
* Erase, overwrite or corrupt data on a computer
* Help to spread other malware such as viruses (by a dropper trojan)
* Deactivate or interfere with anti-virus and firewall programs
* Allow remote access to your computer (by a remote access trojan)
* Upload and download files without your knowledge
* Gather e-mail addresses and use them for spam
* Log keystrokes to steal information such as passwords and credit card numbers
* Copy fake links to false websites, display porno sites, play sounds/videos, display images
* Slow down, restart or shut down your computer
* Re-install themselves after being disabled
* Disable the task manager
* Disable the control panel

To minimise the threats, most PC users will need an effective anti-malware program to remove trojans along with other malware.

Anti-malware and anti-trojan programs

As more computer security developers are extending their product capabilities to address more than one type of malware, the boundary between different types of anti-malware programs is no longer clear-cut and has become blurred.

For example, an anti-virus program such as AVG Anti-Virus covers not only viruses, but offers protection against spyware, adware and others. An anti-spyware program such as SuperAntiSpyware not only detects spyware, but removes trojans, rootkits and other threats. Likewise an anti-trojan program can offer to remove viruses, spyware and other types of malware.

More appropriately, these security products are to be classified as anti-malware programs rather than to be grouped by the name of the products.

In this respect, anti-malware products which are designed to detect and remove trojans more effectively than the others will be reviewed in this category.

How many anti-malware programs do I need to install?

The following extract attempts to answer the aforementioned question and forms part of Gizmo Richards' Support Alert Newsletter, Issue 156, April 2008.

Interviewer: So do you still need an AV program plus an anti-spyware program and an anti-trojan scanner?

Gizmo: For the majority of average users the answer is no. A single competent broad spectrum anti-malware product is enough. Of course, not everyone is an average user. Users who engage in high risk activities, like sourcing their software from P2P services, should load up their PC with all the protection they can get. Similarly, there are users for whom the best possible protection is paramount, regardless of cost or performance implications. Finally, users of freeware scanners who cannot afford [and/or are unwilling to pay for] a premium product may be well advised to use more than one signature-based scanner.

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