My machine was recently infected by a worm called _____. My
anti-virus removed it, but I am still getting _____. How do I fix that
last left-over symptom?
That’s a composite question since I get many variations of it on a
The scenario is simple: you’ve been infected with a virus of some
sort, and your anti-virus program reports, much to your great relief,
that it has cleaned it out for you. And yet, there’s some nagging
leftover specific symptom.
The solution isn’t nearly as simple as the scenario.
If you have left over symptoms, of any sort, then it’s clear that the virus has not been eradicated from your system.
That, at least, seems fairly obvious. Here’s the non-obvious version:
Even if you don’t have leftover symptoms then the virus still may not have been eradicated from your system.
Read that last sentence again, because I want to make sure you understand what it implies.
You get a virus. You clean it up. Your anti-virus program says it’s gone. Your computer behaves normally. Nothing would appear to be amiss.
And yet …
How do you know – I mean really know – that the virus has been completely removed?
Answer: you don’t.
So my answer to your question is this: you can spend a lot of time and effort attempting to track down that last symptom or whatever it is your experiencing, but even if you’re successful at getting rid of it, you’ve proved nothing. Your system may still be infected.
In fact, the fact that there’s a leftover symptom proves that your anti-virus program or whatever other technique you used failed to remove everything.
The rule is this:
Once your machine is infected, it’s not your machine anymore.
I’ve discussed this before, but the fact is that once you’ve become infected there is simply no way to completely remove the virus, and know that you’ve removed all traces of a virus. There are exactly two approaches that work:
restore from your most recent complete backup prior to the infection.
reformat your hard disk and reinstall the operating system from scratch.
If you haven’t been backing up, then really you have only one option.
Yes, that’s painful. Very painful.
That’s why prevention – through appropriate tools, technologies and behaviors – is so much easier and cheaper than the cure.
OK, so I know that you don’t want to follow my advice. You were infected, you have a symptom, and you’re not about to reformat your machine just to get rid of it, even though I’m telling you that you should.
Here are some things to try:
Google the specific symptom – be as specific as you can be when you search. The problem is that each of these leftover issues will likely have its own unique set of removal instructions. And there are probably thousands of different little issues like this – there no single place you’re going to find all the answers.
Use System Restore – I don’t recommend it as a solution by itself but it’s possible that it may help in certain situations with certain symptoms.
Try a repair install of Windows – as part of a longer series of steps a repair install may re-install enough of the system or its settings so as to get rid of the symptom you’re experiencing.
Moving forward I’d also want you to learn from this lesson and take some steps to protect yourself more completely in the future so you don’t have to travel this path again.
Start backing up! Regular backups are the closest thing to a silver bullet that can save you from just about any kind of problem.
Learn to use the internet safely! You don’t have to get infected – ever – if you follow some simple rules, and use some simple tools.
But for today’s scenario, for today’s infection, and for today’s left-over symptom I have to repeat myself: the only sure solution is a reformat and reinstall.