How Is a Trojan Horse Transmitted?

By Gigi Starr

What Is a Trojan Horse Virus?

Like the legendary Greek weapon, a Trojan Horse computer virus sneaks in under the radar to wreak havoc on a system or network. According to Tech FAQ, "This is a type of virus that attempts to make the user think that it is a beneficial application...once executed or installed in the system, this type of virus will start infecting other files in the computer." From that point, it's a tough battle to isolate the virus. By the time the user finds out that something is wrong (usually through sluggish performance or odd pop-up windows), the virus may have already transmitted private information like credit card numbers, passwords and account information. An untended infestation will likely result in a crash of the operating system.

How Do Computers Get Trojan Horses?

Most trojans are introduced through careless downloading: email or instant messenger attachments and peer-to-peer files are common culprits. The user clicks on a file, not noting that it has an .exe or other executable file suffix. The program loads and takes root, slowly weeding through the operating system and software. Some trojans are so advanced that they can tap into an address book, email each person, and attach itself to the outgoing mail.Trojans can also transmit through networks, especially ones that don't have effective firewall or anti-virus protection. If one trojan is opened from several terminals, the infestation can quickly spread to servers and critical files. From there, thieves can remotely download client credit card information. Several security breaches with thousands of compromised names have made headlines in the last few years alone.

How Can People Fight Trojan Horse Viruses?

"The best way to prevent a Trojan Horse Virus from entering and infecting your computer is to never open email attachments or files that have been sent by unknown senders," Tech FAQ advises. TR Brown of Security Pro News suggests always keeping anti-virus software up to date, installing a trusted firewall and staying away from downloads from unknown sites. Also pay attention to clicking links from Google and other search engines; they'll often report suspicious or potentially dangerous content near the link. Trojans are nasty characters, but they're easy to avoid if you utilize the right tools.