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“psyb0t” Worm Infects Routers

Two router options, both of which I’ve said are security risks (see This Router Configuration Option Can Be Dangerous), can now be exploited to turn routers into zombie botnet members. My latest post at Security Corner, Worm Targets Home Networking Equipment, gives details and references to more news items. You can read those if you want, but for now, here’s what you should immediately do:

  1. Power cycle your router.
  2. Disable WAN-facing telnet, SSH or web-based configuration interfaces.
  3. Change the passwords to something unguessable (see this article).
  4. Upgrade to the latest firmware.

If you’re not sure how to handle this, find a geek who can. While the hacker who wrote this worm appears to have disabled the botnet’s control center, others will follow and it could get ugly.

You should also read and apply the Safe Computing Tips available as a free PDF download. Just click on the link to the right.

As always, I’m looking out for you.


The Geek


Articles Released at EzineArticles Site

I’m now an expert author for You can check out my public profile by clicking that Ezine@rticles icon over there, or you can click here. What is EzineArticles? you ask. Here’s what they do: is a matching service — bringing real-world experts and ezine publishers together.

Expert Authors & Writers are able to post their articles to be featured within the site. Our searchable database of hundreds of thousands of quality original articles allows email newsletter publishers hungry for fresh content to find articles that they can use for inclusion within their next newsletter (up to 25 articles per year per our Publisher TOS).

My first two articles have just been published. If you’re a newsletter publisher or webmaster, check out the site and my articles and put them in your next project:

Do You Recognize the Four Early Warning Signs of Hard Disk Drive Failure? (Click the link to the right if you need data recovery services.)

Five Essential Steps to Online Security

Watch for many more to come.


Why Your Wallet is the Best Password Manager

Although I use them to store passwords for sites that don’t require much security, password managers are something I generally stay away from. Why? Because they store the information on my hard drive, a thumb drive, or a website, all of which could be compromised by a determined hacker. Even a relatively unsophisticated hacker could exploit an unpatched vulnerability leaving my passwords open to inspection. My personal security policy is to make it as hard as possible for someone to get to my passwords.

So, I write them down and keep them in my wallet.

Yes, that is the most secure “password manager” there is. No one can get to your wallet from the Internet or your PC. Passwords written on a piece of paper and stored in your wallet are nearly impossible to compromise – someone would have to steal your wallet (or you’d have to lose it) to get at them. How likely is that? I’m 55 years old and have never lost my wallet or had one stolen. Even if someone did get hold of wallet, they wouldn’t know what sites the passwords apply to. I have a secret code that tells me which password goes with what site, and no one is likely to be able to decipher it.

Just be sure not to write down your username with the passwords.


The Geek

Filed in: Password, Security, Tips

How to make a bootable thumb drive virus scanner for NTFS: 2008 update

Once again, in May 2009, I have had to revise this article because Avira’s updates no longer work (thanks, Cindy, for your help in pointing out the problem to me). You can find the latest revision here as well. This new revision supercedes all previous articles I have posted on this subject; specifically, these two:

“How to make a bootable thumb drive virus scanner for NTFS” is the second most popular article on this site, outranked only by “My Computer Won’t Shut Down!” and I thank you for visiting Ask the Geek for advice on these issues. Because of the continuing popularity of the thumb drive virus scanner, I want to make sure you have up to date and relevant information. The two articles listed above are outdated.

The original DOS-based version of the thumb drive virus scanner used F-Prot Antivirus for DOS, one of the best and most popular DOS-based? scanners for nearly 20 years. Unfortunately, F-Secure is no longer updating the virus definitions for that version. In fact, the F-Prot virus signatures are now almost two years old, making them virtually useless. Other vendors are following suit. I’ve had quite a bit of feedback asking me if I could solve this problem and provide an updated method of offline virus scanning.

The good news is that, yes, I’ve solved the problem, thanks to the fact that several vendors offer free bootable rescue CDs for download. Most of these run under some flavor of Linux and after a bit of hacking, I found it’s a simple matter to make a bootable thumb drive from the images.

Note: Avira has changed the ISO image *again* since this article was first posted. I have had comments from some people that the new ISOs just don’t work right on the thumb drive. As of May 2009, the VDF updates cause the old version to fail. I have revised the steps below and updated the BLTDVS toolkit. Because of? the popularity of this toolkit, I am getting bills for excess bandwidth useage. If you find this toolkit useful, please consider making a donation by clicking the “Donate” button. As soon as I am notified of your donation (any amount, minimum $1), I’ll send you the link to the toolkit that contains the ISO image I originally tested.

I chose the Kaspersky Rescue CD from Kaspersky Lab for my latest incarnation of the thumb drive virus scanner. Since it runs under Linux, it has native NTFS read/write support making it unnecessary to use any third party tools like NTFS4DOS (which is still available, but no longer supported by Avira).

Here’s how to be up and running with your own copy of my latest tool in just a few minutes. I’ve made it easy by providing everything you need, except the rescue CD image:

  1. I no longer require that you make a donation, but would appreciate it greatly. I’ve worked hard to keep the BLTDVS toolkit up to date and will contintue to do so.
  2. I do require that you sign up on my list. That is the only way to get the download link and password for the BLTDVS toolkit. Once you sign up and confirm your subscription, the welcome email will give you instructions, a link to the new toolkit, and the password.
  3. If you bypassed the fade-in sign-up form when you arrived at this page, you can click here to go to another sign-up page or click on Sign Up! in the toolbar to the right.
  4. Download the BLTDVS toolkit from the link I send you.
  5. Extract the folder to the root of your hard drive.
  6. Download the Kaspersky Rescue CD ISO image
  7. Move the CD ISO image to the BLTDVS_toolkit folder?
  8. Plug in your thumb drive.
  9. Open the BLTDVS_toolkit folder and navigate to the DriveKey folder.
  10. Run HPUSBF.EXE (command line version) or HPUSBW.EXE (windows version) and format your thumb drive using FAT or FAT32. Deselect the “Create a DOS startup disk” option.
  11. Open the BLTDVS_toolkit folder and copy or move its contents to your thumb drive. Don’t move the actual folder.
  12. On your thumb drive, double-click avrescd.bat. This will extract the necessary files from the ISO image to your thumb drive. Be sure you specify the right drive letter for your thumb drive.
  13. Once the files have been extracted, makeboot.bat will be called automatically. See the caution in the next step!
  14. CAUTION! This step is dangerous! Heed the warning message. Please verify the correct flash drive letter is being displayed before proceeding. Do not run this file on your hard drive or your current MBR will be overwritten rendering Windows unbootable. (This isn’t a complete disaster, but it takes some geeky knowledge to fix it.)? NOTE: If you are usingVista, you may see a “failure to update the MBR” error. In this case, right-click the file and specify “Run as administrator.”
  15. Hit any key to exit. You now have bootable Linux thumb drive virus scanner that will handle NTFS drives as well as most other formats.

One really cool feature of the Kaspersky program is that it will allow you to update it over the Internet as long as you’re plugged into your network. It doesn’t work well with a wireless connection (which both of my laptops have), but I haven’t had a bit of trouble getting an address and updating when I’m plugged in.

Another great feature of the program is that it has a built in file manager, so you can also use it to recover files from an infected hard drive without having to boot into the native OS.

As always, feedback is welcome. I want to know how this tool is working for you.

(Thanks to PDLA ©2007 and Lance ©2008? Syslinux is ©1994-2006 H. Peter Anvin for the files used in this tool.)

The Geek

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How to Secure Your Computer – 14 Maxims

This post is long overdue. Having completed my How to Secure Your Computer series of articles, it’s time to get links to all of them organized on a single page.

The series debuted on January 4, 2007 on my Lockergnome blog, Ask the Geek, Too. I continued to post them there until March, 2008 when other commitments forced me to put that blog on the back burner. (Chris Pirillo and the Lockergnome gang have been gracious enough to keep my content live and I hope to contribute there again in the future.) I have since revised and re-posted all of the maxims on my Security Corner blog, most of them having been given more catchy titles. You will find the entire archive in descending chronological order in the Security Maxim archives – Security Corner.

Below are links to the original postings up to and including Maxim #11 which was the last one posted to Lockergnome; nos. 12, 13, & 14 are new and appear only at Security Corner.

2007.01.04 – How to Secure Your Computer: Maxim #1
2007.02.22 – How to Secure Your Computer: Maxim #2 (or, How Not to Invite Attackers Into Your PCs and Networks)
2007.03.03 – How to Secure Your Computer: Maxim #3
2007.03.14 – How to Secure Your Computer: Maxim #4
2007.05.30 – How to Secure Your Computer: Maxim #5
2007.06.27 – How to Secure Your Computer: Maxim #6
2007.07.25 – How to Secure Your Computer: Maxim #7
2007.07.26 – How to Secure Your Computer: Maxim #8
2007.07.28 – How to Secure Your Computer: Maxim #9
2007.08.17 – How to Secure Your Computer: Maxim #10
2007.10.29 – How to Secure Your Computer: Maxim #11

I will soon make available a complete compilation of these articles for download as a free bonus to everyone who subscribes to my feed.

The Geek


WiFi Security–The Only Way is WPA

One of these days, I’m going to catch up with this site and get links posted to all the new content I’ve been generating over at Security Corner. For now, I thought you’d like to read the latest article in the How to Secure Your Computer series. I’m up to 13 now. The next post here will be a list of all of them. Here you go:


The Geek

Filed in: How To, Security, Tips

How to Write Down Your Passwords and Not Worry About Someone Stealing Them

I sometimes enjoy playing with codes and ciphers. In fact, a long time ago (eighth grade, 1966), I got my introduction to cryptography from a book aptly named Codes and Ciphers written by Alexander d’Agapeyeff. My friends and I had some good laughs getting caught passing encoded notes in class; the nun couldn’t decipher them. Being an Edgar Allen Poe fan, I was fascinated by his story “The Gold Bug,” which centers on the solution to a cipher that turns out to be a map to hidden pirate treasure. And then there’s that bit with Ralphie, the hero in the classic holiday hit movie, A Christmas Story, where he anxiously awaits the arrival of his “Little Orphan Annie Secret Decoder Ring.”

But I digress.

I know this isn’t a new concept by any means, but the application of simple cryptographic principles can allow you to generate passwords using patterns that you can safely write down. One of the key elements of authentication is “something only you know” and you can use this to generate secure passwords with simple substitution and transposition ciphers. (WARNING: playing around with this stuff can be habit-forming!)

Let’s take a simple example of a substitution cipher based on a date. This one uses two levels of secret “keys”: 1. a clue or mnemonic for the date; 2. an abstraction of the encoding algorithm. We’ll use Abe Lincoln’s birthday in numeric form–02/12/1809–for our plaintext, leaving out the slashes, i.e., 02121809, which will result in a strong, eight character password. Now, for the first key, we can use “BDAbe.” This immediately reveals the plaintext, but means little or nothing to anyone else. (NEVER use your own birthday, for obvious reasons.)

Next, we decide to use alternating shifted characters, beginning with the first character. So, for key two, we make an abstraction of that: %x#, for example. It doesn’t matter what characters you use, only that they clearly represent shifted and lower-case characters; you could just as easily use AyT or !2@. The pattern of shift-lowercase-shift on the keyboard is what matters to you; the characters mean nothing else. Put the two keys together and you have this: BDAbe%x#. That’s your cipher pattern, the “something only you know,” with an added level of complexity: it’s something only you know (the plaintext) and only you know what it means (the encoding pattern). Anyone who sees BDAbe%x# will have your keys, but it’s likely they won’t have a clue as to what to do with them. Write it down. Post it all over the place. Buy an ad in the newspaper. Tell everyone you know. Who cares? It isn’t your password and only you know what it means; but, it looks like a password and serves as an effective deception.

Finally, we generate the actual password using our cipher pattern of alternating shifted and lowercase characters, so 02121809 becomes our ciphertext of )2!2!8)9: eight characters, each having one of 96 possible choices. In a brute force attack, a modern PC, capable of guessing 10 million passwords per second, would take 23 years to go through all possible combinations of an eight-character password with a 96 character selection space. Not too shabby, eh?

For website logins where high security isn’t a concern, you can drop the “www.” and use the rest of the URL as your plaintext. In this case, you only need to write down the password length and encoding pattern. Let’s say I have a login on the site I don’t care if someone reads the news using my password, so tight security isn’t a concern. I decide on a pattern of lowercase-shift-shift and decide to use a six-character password. The encoding pattern is x%^, so I can write that down as^. Who’s going to know what that means? The password would be nYTiME. At only six characters and despite being based on the URL itself, that password is still relatively secure: it would take a hacker 33 minutes to crack your password; he’d be able to set up his own account in less than 2 minutes. And why would anyone want to crack your password? doesn’t ask for any personal information other than your birth year and zip code, nothing that’s worth anything to a criminal hacker.

I encourage you to come up with your own method of applying this to your passwords, and of course, I welcome your comments and questions.

The Geek

Have a question? It can be about anything from cooking to science, whatever you’re interested in: Click here to Ask the Geek! Kenny “The Geek” Harthun has been playing with geeky stuff since 1965. He’s a former research scientist, currently works as a Microsoft Certified Systems Engineer at Connective Computing, Inc. and loves to learn about anything and everything.

Filed in: Answers, How To, Security, Tips

Will an improper shutdown harm my computer?

Error Message I get this question often enough that it’s time for a detailed post. Today, I’m answering Valania’s question:

When you improperly shut down your computer does it harm your computer hardware, or anything else in your computer?

Valania, by “improperly shut down,” I assume you mean pressing the power button instead of clicking Start->Shut Down from Windows. This won’t harm any of your hardware. After all, Windows powers off the PC, too, when you do a “normal” shutdown. Think of it this way: Your computer is made from components similar to those in any other electronic device–like a stereo or TV–and you turn them on and off all the time without any bad effects. However, the data on your hard drive can be damaged by an improper shutdown.

This was a big problem back in the days of Windows 95 and 98. When you restarted after an improper shutdown, the operating system would come up asking you to run scandisk to correct hard disk errors. It’s not as big a problem with Windows XP, but it does happen. If you remove power from the system while data is being written to your hard disk, the data will be incomplete and appear corrupt. Usually, though, a system hang severe enough to warrant pushing the power button is the result of a problem reading or loading a file and your PC won’t suffer any ill effects if you power it down.

The Geek

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Who Else Wants to Lose Their Computers to Lightning This Year?

Last week, my friend Allison’s home was hit by lightning taking out her satellite TV dish, her TV, microwave, stereo, and both of her computers. She never thought it would happen to her. After all, her two PCs had been running fine and never had any problems. She would turn them off if storms approached, a good practice.

But, like most people, she had all her stuff plugged into those cheap power strips you can buy anywhere. Bad idea! Most of them have no protection against power surges and the ones that do wear out after a couple of years and should be replaced.

Based on the damage, it was easy to see that the satellite dish took the direct hit and the rest of the damage was caused by a surge in the power lines, so a proper surge suppressor might have saved her PCs.

Don’t let Mother Nature and the local utilities rob you of your computers; put proper surge protection in place. American Power Conversion makes some of the best surge and battery backup equipment going. I recommend them highly.

The Geek

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Filed in: Answers, Computers, Tips

How to Secure Your Computer: Maxim #5

To say nothing of Microsoft Windows, there are few, if any, application software packages that are free of security vulnerabilities. The SANS Institute publishes its Top- 20 Internet Security Attack Targets on a regular basis and Secunia currently lists 14,043 pieces of software and operating systems with vulnerabilities. That’s the bad news.

The good news is that most reputable software companies, when informed of a vulnerability by security researchers, promptly issue a software patch to fix it. These are widely available to the public for free download or through update features built into the software packages. Windows allows you to turn on Automatic Updates (which you should do). Check the Help menu in other software packages for the update feature.

There’s more bad news, however. Most people don’t keep up with patches on their systems except for Windows updates. Which brings us to computer security Maxim #5:

A vital part of PC security is keeping up with software patches for ALL of the software on your system, not just the operating system. Where it is available, use the software’s automatic updates feature.

The Geek

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Filed in: Computers, How To, Security, Tips
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