Last night, I downloaded an AVI video file and I've always had trouble playing AVI so I searched the internet for a free AVI player. I found one but somehow, when I ran the program, nothing happened. I (very stupidly) couldn't be bothered to uninstall it. I opened VLC media player and it worked fine. This morning, however, I turn my computer and get a warning from AVG Anti Virus that the AVI player I installed was a Trojan Horse. I moved it to the Virus Vault and wiped the files. I then went into the Program Files folder and deleted the Avi Player folder. I also did what Wikipedia saaid and deleted my temporary internet files. Anyway, if anybody can explain what a Trojan Horse is and if I have took the right methods to get rid of it, I would be grateful.

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Well the trojan horse malware is named after the historical invasion of troy i believe. If you remember the opposing army gave the city of Troy a HUGE wooden horse, like the size of a house and they took it inside their gates and over night the horse opened up and enemy soldiers spilled out opening the gates allowing their friends to come in and destroy the city. The most genius siege ever.

A trojan horse software works in the same way. It is usually in a program that looks useful (like the horse in the siege) and in this case it was the AVI player you downloaded, it looks useful but inside there was a threat and as soon as it's on your computer it begins to spill out its bad code onto your system. From here it can do anything, install a virus of other malware, install keyloggers, download files, upload files, destroy your hard drive etc... effectively destroy your computer (same as destroying the city in the siege)

and thats what they are and why they are called Trojan horses.

As for removing them i think you did the right thing. You should treat them as any other malware, head your AV warning and quarantine them (dont delete them outright at first in case they have infected system files and crash your machine) then delete or quarantine any files its likely they might have infected. IF possible check for the name of the trojan and then find out what it does. EG if it is a trojan that downloads other malware a good step is to tighten your firewall or disconnect from the net untill you remove it. Once you feel it is safe again do a full system scan or even better, a boot-time scan if your AV lets you and you should be safe again.

to avoid them in the future always download from reputable sites, eg download.com etc... so you know they arent deliberately infected and you should scan files on download.. i dont always but i know i should, its only a matter of time.

 

 

 

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Well, a trojan horse is something like a 'Spy' that disguises itself as a friendly software or something, or maybe even friendly software. What is does is to lure you into a sense of false security and make you run the program, and in some cases (with Windows Vista) even give it full administrator security clearance.
So, a trojan horse is a virus that embeds itself into other programs which makes you install the trojan along with the friendly program, the moment you install the trojan is activated, some are there to install adware, some are to create 'backdoors' and others just mess up your computer.

To get rid of them any good anti-virus program would do, I see you use AVG. AVG would be good enough to remove most trojans/viruses but for some you'll have to use special software specially designed to take care of that virus/trojan horse...

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Ah this has to be said... A trojan isnt a virus because a virus is essentially a stand a lone piece of code that NEEDS to infect another program to run, so if you took a virus and put it on a blank disk and ran that disk with no other programs, not even an operating system, then technically it shouldnt be able to run. So technically a Trojan is Malware not a virus But for all intensive purposes thinking of it as a virus doesnt matter!

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My computer seems to be working fine. I've installed a firewall so that blocks basically aboiut every application from accessing the internet that I don't want. My computer hasn't actually changed at all. If it wasn't for AVG, I woudln't have known.

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Judging by what you've done and said you've probably hit the trojan well and got rid of it which is good news, and the firewall will really help in the future at both stopping you from getting them and minimizing the damage done.



And thats the problem, a lot of people assume that a firewall will protect them well enough but as this demonstrates you really do need an AV because a firewall wont and cant stop everything. Glad to hear its solved though

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From my understanding, a Trojan horse is how it was depicted in relation to the Siege of Troy... but isn't it, by defition, only dangerous if someone exploits that "backdoor?"

Trojans themselves can harbor other malicious code, such as a continuous creation of an obvious virus to mask the Trojan itself (or at least keep attention away from it) or as an additional bit of salt to the injury, and it really isn't a virus by itself (from my understanding), but simply a program that assists hackers in gaining access to a machine. (Antivirus programs will detect them, however.)

One infamous (but rather harmless) Trojan that I remember fooling around with was Netbus. It was simply a program that you could run on your own machine and actually target another machine by IP address, but the things you could do with it were rather limited and for annoyances only (by its GUI, anyway): killing windows, forcing a shutdown, opening and closing the CD/DVD drive, and "sending" alert messages.

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Today most of the net surfers suffer from the trojan horses.I don't know exactly but I think it is a malware or a spyware.You said that you have move to the virus vault through AVG.If you have professional AVG version then it is good ,But if you have free edition then I think it is not good...Because I also used AVG free edition and i had a similar problem like you but even after moving that virus to virus vault after few days my computer started hangging....I think the virus was still there somewhere in my computer.

But then I switched to Norton Internet security 2007,I scanned my computer then and got approx 50 infections ...so that virus was spreading.....

so here through my post ,I don't want to others about my problem.But to inform others that it is not a good idea to rely on free edition antiviruses.
so If you can have norton ,then its good.Otherwise if you cannot afford then try AVAST ANTIVIRUS HOME EDITION..its better than AVG ANTIVIRUS,trust me because I have tried both and I liked the former one more better than the latter one.

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