Technology in terms you understand. Sign up for the Confident Computing newsletter for weekly solutions to make your life easier. Click here and get The Ask Leo! Guide to Staying Safe on the Internet — FREE Edition as my thank you for subscribing!

My anti-virus cleared something off my machine. Should I change my passwords?

Question:

When I opened Internet Explorer, a message popped up from my
anti-virus program (AVG Free) advising that Trojan Horse
PSW.Lineage.BKG was detected in a .dll file of a bin file of the Ask
Toolbar in Program Files. Two options were offered: "heal" or "move to
virus vault." Unclear of what the difference is, I chose "heal" and the
Ask file along with a restore point were moved to the AVG virus vault.
Several follow up scans in safe and regular mode as well as an online
Kaspersky scan showed no malware.

Research yielded no info about PSW.Lineage.BKG, even on the AVG
site, but other PSW.Lineage Trojans are mentioned online. It seems that
this Trojan attempts to steal passwords, and BKG "may" be an
abbreviation for "banking". I do not do online banking but do use my
credit card on the Internet. I use Windows firewall and an Actiontek
modem/router.

Is it necessary now to change all my online passwords, or can I feel
reasonably sure that this has been taken care of?

The short answer is probably not ... but.

The problem is that we don't actually know exactly what happened,
and the not knowing means that there's some risk.

]]>

When your anti-malware software detects and removes an infection, it can happen at either of two times:

  • Before the malware had a chance to actually execute and infect your machine

  • After the malware had been executed and had infected your machine

The problem is that based on your question, I can't honestly tell which it was. In fact, it's even likely that depending on exactly what your anti-malware software reported, you might not be able to tell which it was either.

"If caught after infection ... well, it may be too late."

The difference, of course, is that if the malware is caught before infection, you're likely quite safe. If caught after infection ... well, it may be too late.

Now, the reason I waffle at all is that most real-time scanners will fall into the former category, catching things as they arrive (in "real time"), and blocking them from ever infecting your machine. Since you indicate that this message has popped up in Internet Explorer, that's typically the result of a real time scanner.

On the other hand, you indicate that it was "detected in a .dll file of a bin file of the Ask Toolbar in Program Files." That typically means that the infection is already in place, since the infected file appears to have been installed into its working location.

Thus we're left not really knowing exactly what happened. And as a result we don't know exactly what the risks are that you've been exposed to.

I think you can guess where I'm headed with this.

In the words of Dirty Harry: "... you've got to ask yourself one question: Do I feel lucky?"

In your shoes ... I'd change my passwords. It's an inconvenience, perhaps, but better safe than sorry.

Do this

Subscribe to Confident Computing! Less frustration and more confidence, solutions, answers, and tips in your inbox every week.

I'll see you there!

6 comments on “My anti-virus cleared something off my machine. Should I change my passwords?”

  1. I agree. Changing you passwords is a lot less of a hassle than having your identity stolen. I change all of mine every 6 months. I keep them in a spreadsheet which I store on a flash drive in an encryoted file (TrueCrypt) in a safe place. I update my spreadsheet on a computer that is not connected to the internet and that file is never on a harddrive of any computer that is connected. Call me paranoid but I have two friends that have had their identity stolen in the last six months.

    Reply
  2. Leo, It could have been a false positive. In which case the danger is that AVG deleted something harmless, or possibly deleted an essential file. All antivirus programs “detect” a certain number of non-existent viruses, particularly if ‘heuristic search’ is enabled.

    Reply
  3. I noticed in the question that they stated that they have an “Actiontek” modem/router. MY Actiontek modem is JUST a modem – NOT a router! BEWARE!

    Depends on the model. I once had an ActionTek that WAS a router.

    – Leo
    06-Feb-2009
    Reply
  4. Leo, thank you for the article.

    In a situation like this, would it have been possible for a “two-way” firewall, such as Zone Alarm for example, to keep the Trojan from stealing the passwords in the first place?

    Best you can say is “maybe”. The problem is that once you’re infected there’s no way to know that the firewall is in fact blocking it.

    – Leo
    09-Feb-2009
    Reply
  5. Leo, based on what you stated above about when a malware executes, is it correct to say that if my anti-malware software detects a malware during a manual (on-demand) or scheduled scan when I am NOT connected to the internet, then the malware has already executed and have already infected my PC? Thanks…

    All it means is that the virus is present on your machine in some form. It might be in an executable file that you’ve downloaded but not yet run, meaning your machine is not yet infected, or it’s present in your system in some infected form.

    Leo
    17-Jan-2013
    Reply

Leave a reply:

Before commenting please:

  • Read the article.
  • Comment on the article.
  • No personal information.
  • No spam.

Comments violating those rules will be removed. Comments that don't add value will be removed, including off-topic or content-free comments, or comments that look even a little bit like spam. All comments containing links and certain keywords will be moderated before publication.

I want comments to be valuable for everyone, including those who come later and take the time to read.