How does one remove a trojan from a computer?

My computer apparently got implanted with a trojan from a bogus "college". I have no idea how to fix this issue; can anyone help me out?

Back up your important files, if they aren't already.

Scan with an antivirus program of your choice, (I recommend Avast.) which should be able to remove it.

If that doesn't work, try a different AV program.

You can also try booting from a Linux live CD and seeing if you can remove the files manually.

If everything else doesn't work, nuke it from orbit by formatting the disk and reinstalling the OS. It's the only way to be sure, but is obviously very time-consuming.

edited 27th Mar '11 9:26:45 AM by Yej

Also, try googling the name of it or wherever you got it along with «removal instructions».

I've gotten it fixed. Thanks mates. Turns out that someone -coughmumcough- had taken off my security to run something. Just had to set it back up and run WD.

edited 27th Mar '11 10:29:20 AM by Diamonnes

Backup relevant data. Format. Reinstall OS. Reinstall Programs. Check data for trojan. Restore clean data.

Trojans are nasty things: There is No Kill like Overkill when you're dealing with'em.

We sound like we're taking apart an Eldritch Abomination with a precision strike. I love these forums.

edited 27th Mar '11 11:12:02 AM by Ekuran

For future reference, the one anti-virus software that I found that works best is Malwarebytes. It has picked up the most viruses in the past, is small in size, quite fast, and portable. Thus, whenever someone needs their computer cleaned, I just grab Malwarebytes first, let that run through and then look at the situation.

edited 27th Mar '11 11:13:53 AM by Usht

If you think about it, they are kinda similar. Viruses and trojans shouldn't exist. They're pure evil. And they corrupt everything they touch. Eldritch Abominations defy reality. They are never good news. And they turn normal humans mad.

Viruses exist because people are malicious.

I'm not sure how much of an insult you'll take this, but give your mum a smack.

Eh, don't smack her, just tell her to never ever do that again.

This may be unrelated to trojans, but is there a virus that causes an Internet connections to blink off every thirty seconds for a few seconds and then reconnect? That's a problem I have with this computer, but not with any of the other computers on my Internet connection (although the Mac loses its connection altogether every time the phone is being used).

Alternately, teach her how to make security exceptions for specific things that require Java Script, popups, et cetera. ...after verifying that whatever she wants to do is actually safe, of course.

Malwarebytes is definitely a good choice in scanners, but you should have multiple levels of redundancy for this kind of thing, too. While one good brand may fail to catch something sometimes, two or three high-quality brands will keep you covered as much as it's possible to be covered.

If you don't do this already, in the future I'd recommend running your scans in Safe Mode - this prevents many viruses, etc from launching automatically and will minimize the chance of interference. If you try to scan for and delete a particularly clingy infection outside of Safe Mode, you may find the problem coming back the very next time you reboot your computer because it was active as a hidden process during the scan. F8 during the boot process lets you get to the menu for Safe Mode on most machines.

Edit, for chihuahua 0: Yes. Yes, there is. ;) It might not be an infection, but you should probably go through a few scans just to be safe.

edited 27th Mar '11 12:37:52 PM by Karkadinn

Which leads to a different trope all together.

I had scanned the computer multiple times with different settings over a year, and it hasn't detected a virus (most viruses probably wouldn't have time to download themselves onto my computer). So either the virus is deep enough in the system to evade scans, or it's because my computer is so old.

How are you connecting? Do you have a hard connection or are you using wifi? Also, are you using dial-up, DSL, cable?

edited 27th Mar '11 2:24:39 PM by DrunkGirlfriend

This computer has a hard connection, while the other ones are wifi and Airport (for the Mac). I think it is DSL, with Netgear for the wifi. I'm not sure if it is two different connections, or just one connection.

Oh, the sweep reports no traces and viruses, as usual.

edited 27th Mar '11 3:45:31 PM by chihuahua0

Maybe you have a short in your cable somewhere. Have you tried swapping out ethernet cables from the modem to your computer?

Having issues again. I think the name is W32/Blaster.worm or something similar. I looked up the instructions to uninstall, says I have to use the Task Manager. Problem is, I have a commercial antivirus company screaming (literally screaming, it's actually making the sound of a squealing pig) that it's infected.

This thing literally will not let me access my own control panel until I pay fifty bucks for it.

I'm pretty sure this is illegal.

^ The anti-virus software locks you out of your OS' control panel? That is illegal.

Looks like I'll have to wipe my computer.

MY PRECIOUS FILES. ;_;

And then...

Dia's gonna hafta sue a bitch.

Just run a Linux Live CD, backup to elsewhere... you'll be laughing a couple of minutes after you reinstall your OS.

Also, lol at people saying "malware does bad things? That's illegal"

edited 2nd May '11 8:36:29 AM by SilentReverence

@Silent: It isn't the malware, it's an antivirus company. If it were JUST the worm, I could nuke that thing in two minutes, but this Goddessforsaken thing won't let me access any part of my computer.

Looks like me and the Library are gonna be good friends. :/

...And that's why you run a Linux Live CD. To bypass the already scrambled installed OS. Unless the "antivirus" damaged the bios too or something. Any 2009 or later live disc should pick NTFS partitions and let you backup the files to an external drive just fine. Then from the same disc nuke the partitions and install from scratch, to prevent the virus from backuping itself during the install procedure (I've seen some who do that).

Uhm, what's it called? It might be one of these malware things masquerading as antivirus.