The most common recommendation in preventing a Trojan horse infection is to keep the computer up-to-date. Available security updates for Windows, Mac or Linux operating systems and other installed software in a computer should be installed at earliest available time. Most security updates will prevent exploits that target the vulnerable component or applications, thus preventing infection of a Trojan horse.
It is also recommended you install an antivirus program in any PC to provide real-time protection against Trojans and other types of malicious software. The antivirus software should also be used to regularly scan the computer; not just depend on the on-access protection. A regular system scan allows an end-user to verify that all files are clean and malware-free. It is is also recommended to review the available setting of your antivirus software by ensuring all files with all types of file extension, no extension or double file extensions are scanned.
An extra layer of protection is also recommended, and this is done by using extra security tools or best practices:
- Use a customized Hosts file in Windows, Linux or Mac computers.
- Configure the security settings of all applications by using the maximum available options.
- Disable or remove unneeded browsers, Windows or email plugins.
- Be informed on the latest security and privacy issues that affect installed programs.
- Do not open email attachments from an untrusted sender, and ensure the attachments are scanned by antivirus software before opening, if you are expecting an e-mail attachments.
- Do not fall into clicking or allowing an install of plugins for browser, media player or instant messengers if you are not actually aware what it is for.
- Keep your personal data private by password protecting private information or files, and use a master password.
Firewall programs should also be enabled in Linux, Mac or Windows because Trojan horses often make an outside connection. A firewall program that will monitor outgoing traffic should be used. This prevents a Trojan horse or any applications in general to use an Internet connection without your approval. If a firewall program prompts to allow an outside communication by a program that you did not install or do not know exists in your computer, the antivirus program may have missed the infection already. Immediately run a scan using an on-demand scanner to check the security status of the computer.
Image credits: TrojanHunter screenshot http://www.trojanhunter.com/trojanhunter/, screenshots taken by the author.