About Weak Passwords

Martin Brinkmann
Mar 27, 2007
Updated • Jun 1, 2013
Security
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12

I discovered the article "How I would hack your weak passwords" yesterday and was not sure back then if I should comment on it or not. Today I decided that it would make sense to provide you with my point of view, so here it comes.

The author of the article details how he would try and gain access to another user's passwords and accounts. His first approach would be to use the most common used passwords by users on the net. He needs information about your personal life for some passwords but those information can be obtained pretty fast through social engineering. Trying those "top 10" passwords should provide him with access to at least some accounts statistically speaking.

The common password approach is the most direct attack one can launch on someone's online account. All you have to do is log in with the user's email address or username, and try different passwords that are commonly used or that you can associated with the particular user.

His next approach is to brute force the passwords on websites with weak security. This is more or less an automated version of the password guessing method. Instead of having to try manually by yourself, you let a program test hundreds or thousands of common passwords.

Many sites and servers offer protection against these kinds of attacks. This often includes banning IP addresses or sometimes even blocking login access to an account for a select amount of time to avoid further attacks.

But the brute force programs that he suggests are way outdated. Brutus? wwwHack? That's last millennium. Current state of the art brute force programs to crack basic authorization and form protected sites are C-Force or Sentry. The brute force approach has one disadvantage. If you do not know the username you have to try username and password combinations and there is no guarantee that you will discover the combination for the user that you want to hack.

You could get login details for other users which are absolutely worthless to you. This means, brute forcing is only an option if you know the username of the user.

There are actually two ways to brute force an account. The first would be to use generated lists of usernames and passwords or try combinations to get into an account. The second to try every char combination possible. It should be noted that the second option could very well last several years or even centuries depending on the size of the selected password.

So, brute forcing is not really an option and he is not explaining how he would get the username of the user in question except mentioning cookies. Cookies are stored on the targets machine which would mean that he needs either access to that machine or an exploit to get them while the user is online. Not very practicable.

So, what can users learn from his analysis ?

  • Don't overuse passwords, it's more secure to use different passwords. If you only use one password you are giving away access to all of your accounts, literally speaking if that one password breaks. Even if you select a secure one, it is still possible that a server attack may get it for the attacker, for instance if a web service saves passwords in clear text in a database.
  • Don't use passwords that are easy to guess or common. No names, no sport teams, relatives, pets, work related, hobbies , and so on
  • Use numbers and special chars if possible to increase the security of the password. Remember that size matters.
  • Write them down locally and put them in a safe or use a software that encrypts them. You could for instance use a True Crypt partition to store a textfile with your passwords in them
  • Every password may be important to retrieve additional information about a user, never choose weak ones
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Comments

  1. galerion said on November 6, 2008 at 6:40 am
    Reply

    Quote: If you do not know the username you have to try username and password combinations and there is no guarantee that you will discover the combination for the user that you want to hack.

    In travian you can see everyones usernames so its just the password you would need to get into there account.

  2. Matthew Jacoby said on June 25, 2008 at 7:35 pm
    Reply

    Weak passwords are a HUGE issue that, for some odd reason, hasn’t hit the IT Admin mainstream yet. I guess they don’t realize that those sophisticated (and EXPENSIVE) firewalls and intrusion detection systems are rendered practically useless if there is a single weak password on their networks.

    The problem now is that companies are coming up with “Password Recommendations”, or policies they have no way to enforce. Instead of making “recommendations”, I don’t understand why companies don’t REQUIRE a strong password.

    There is a software solutions out there called nFront Password Filter that does just that…it REQUIRES strong passwords on Windows domains. With the option to have multiple policies, different users can be assigned different requirements. Along with its built in dictionary scan and ease of installation, IT Admins can have their networks more secure than ever in a matter of minutes.

    Now there’s no more excuses. nFront Password Filter takes care of all the hard work required to secure your networks.

  3. Avalanco said on September 6, 2007 at 7:39 pm
    Reply

    Hi. Interesting article(s). Weak passwords has been an problem for a long period, unfortunately, it won’t change over an eye blink.

    I was just wondering, these tools mentioned in this article (C-force, and Sentry), where could one be able to obtain these ?

  4. Jim Shepherd said on March 28, 2007 at 9:04 pm
    Reply

    I use Password Safe: http://passwordsafe.sourceforge.net which was originally developed by Bruce Schneier, is now open source and as such, is free.

  5. Raymond Koppen said on March 28, 2007 at 8:15 am
    Reply

    There is also http://portableapps.com/apps/utilities/keepass_portable

    but I haven’t tried that out yet.

    BTW Just to be clear I use the portable version of Roboform, which (can) run off a usb stick.

    Ray

  6. Raymond Koppen said on March 28, 2007 at 8:09 am
    Reply

    Joose : Try Roboform, it detects webpages and fills in the passwords and its free.

  7. Joose Haverinen said on March 28, 2007 at 12:46 am
    Reply

    Would be great if you could find and recommend an free password-software, that would automatically insert the passwords into correct web forms.

    I personally use pretty secure passwords, but only few because it’s quite hard to remember which passwords are used where.

  8. John Pozadzides said on March 27, 2007 at 8:29 pm
    Reply

    Great follow up to my original article, and I had hoped that others would detail the “flaws” in my methodology for the sake of illustrating that what I outlined is only the tip of the iceberg.

    Of course, in the original document I had to consider my reader base (which is generally non-technical) and I needed to make a point quickly, succinctly and forcefully. My primary interest with the article was to make people like my friends, family and neighbors stop to think about it before they chose that next weak password. :-)

    Take care,

    John

  9. Raymond Koppen said on March 27, 2007 at 12:06 pm
    Reply

    I have become a big fan of Roboform, an application that stores passwords for you, this way you only have to remember one skeleton key pass to get access to the other passwords. It can also be used to generate safe passwords for you so you can have a different password on each site. Of course the password database is carefully encrypted.

    Ray

  10. ilo said on March 27, 2007 at 11:35 am
    Reply

    If someone try to brake your password buy using
    your informations in order to change the password
    and email am shur that it will take alot of time
    ti find out stuff like that and you have to be a VIP
    to think that someone could do something like that you.

  11. leny said on March 27, 2007 at 9:59 am
    Reply

    martin, buddy big fan of ur site…u wouldnt happen to know where i can download bruteforce program for OCR Would you ???

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