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How I cracked my neighbor's WiFi password without breaking a sweat

arstechnica.com

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Re: How I cracked my neighbor's WiFi password without breaking a sweat

#51
post #45
post #33

No doubt, this neighbor should have changed his password long ago, but there is a lot to admire about his security hygiene nonetheless. I think it's taken too much for granted that one should change passwords on a regular basis. If we assume that changing passwords more frequently means that we are more likely to use more rememberable - and, thus, more guessable - passwords, then perhaps this is not a fluke. Perhaps…

One should change passwords on an irregular basis (a regular basis is weaker protection than an irregular basis). This is just an additional layer of security, not a perfection. If the password has ever been compromised, a password change policy removes the key from bad hands. Discovered passwords are not always immediately used; in many situations, they are stored for later use, perhaps even sold/traded.

We shouldn't make such proclamations based on reasoning along. Security policy that involves human behavior depends extensively on what humans do. So while a particular security policy may be the safest, most rational thing to do, it may fail in practice if people execute it poorly.

So, if it is true that when people regularly change their passwords, they pick poorer passwords, then perhaps those poor passwords are a larger risk than the risk of maintaining a compromised password. Again, this is not a question of what is the most rational policy. It is a question of human behavior, which means in order to find an answer, we need to study what people actually do.

I googled to see if I could find studies on this, and I did: "The True Cost of Unusable Password Policies: Password Use in the Wild" by Philip Inglesant & M. Angela Sasse: http://www.cl.cam.ac.uk/~rja14/shb10/angela2.pdf I have yet to read it in full, but they do touch on this idea at least some.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#52

Earlier quoted context omitted.

Using the Silica wireless hacking tool sold by penetration-testing software provider Immunity for $2,500 a year, I had no trouble capturing a handshake established between a Netgear WGR617 wireless router and my MacBook Pro.

Using the aircrack-ng suite you can do it for free.

That's exactly what this article points out in the very next sentence after the section I quoted.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#53
post #28
post #21

What is the command for aircrack-ng to generate the pcap file with the handshake? (For those curious mac users, you can simply type "brew install aircrack-ng")

Note that (I think) Apple typically uses Broadcomm wireless chips, which are not the best choice for this sort of thing.

Many modern MacBooks use atheros chips, which work perfectly.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#54

>What's more, WPA and WPA2 passwords require a minimum of eight characters, eliminating the possibility users will pick shorter passphrases that could be brute forced in more manageable timeframes Should I point out that 'password' is 8 characters :) Have there been studies done that attempt to test the hypothesis that when forced to pick passwords that meet some arbitrary complexity threshold most common users pick…

One of the things I try very hard to drive home to people is that WPA2 uses a passphrase and not a password.

I highly encourage people to use something like a favorite movie quote or a line from a book. Something like "Alas, poor Yorick! I knew him Horatio;" is both harder to crack and easier for a human to remember than something like "v3$bk:j".

You're essentially taking natural language, which is something humans are pretty adept at remembering, and turning it into a direct mnemonic for a more complicated passphrase.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#55

So what do I run now instead of Kismac, since it doesn't support anything > 10.7.2? Aircrack with some GUI frontend?

A Linux distro. Don't get me wrong, this isn't an anti-apple rant: I've myself tried to my Macbook laptop to learn aircrack and finally desisted. The most important tools, airodump and aireplay, don't work in Mac, even if you have an injection-capable card. Your best option is try with Linux either in your Mac (I think Backtrack has a Live CD so you don't have to install anything) or in a non-Apple PC.

& A simple remedy for staying on your mac is to use a wireless dongle (USB) that supports packet injection. It's extremely simple to set up in backtrack.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#57
post #56
post #20

You're also screwed if you have WiFi Protected Setup enabled (Its enabled by default in most routers). Once can easily crack a WPA2 passphrase easily in a few hours using a tool like reaver.

Care to elaborate?

Look here: http://sviehb.files.wordpress.com/2011/12/viehboeck_wps.pdf

And here's a link to the tool: http://code.google.com/p/reaver-wps/

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#58

Earlier quoted context omitted.

Anecdotally, most people I know without secure WIFI passwords pick things like: - Their address (sometimes with numerals spelled out) - Their last name - Their child's name - single (common) dictionary word - single (common) dictionary word + one or two digits.

for about 80% of protected home networks i’ve accessed the password ends up being someone in the home’s phone number.. not sure if it’s just because it’s often the only 8+ character string of numbers people readily have memorized or if it’s just lazy isp’s that set it that way (and lazy owners who never change it afterwards)..?

Yep, in public compromises of large sets of WPA passphrases, more than 50% of them are phone numbers. This is why we offer a CloudCracker dictionary which includes every valid NANP number in it: https://www.cloudcracker.com/dictionaries.html

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#59
I found this article to be a bit sensational. It should be titled, "how I paid some experts to crack my neighbor’s Wifi." I’m not trying to dismiss the threat, just put it in perspective. The use of these tools is either expensive ($2500 a year?) or requires a non-trivial amount of expertise (Aircrack-ng).

I did find the article linked within to be more interesting and informative.

http://arstechnica.com/security/2012/08/passwords-under-assa...

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#60

Earlier quoted context omitted.

Look at it this way. Lets say I give you 5 characters to create a password. If you use all numbers then each value can be anywhere between 0 to 9. That's only 10 values! So that's 10 to the power of 5. That's only 100,000 permutations. With letters, assuming standard English, you get 26 per value. Or 52 when we include case. That's a big difference. So lets say I only give you 4 lowercase characters. That's 4 to the…

Sounds a lot like my bank. 5 characters of 0-9 is exactly what they validate their passwords on. Luckily that validation is done only in Javascript, so disabling the check allows you to use any password you want. That doesn't help the average person though.

So you actually tricked the server into setting a password it usually wouldn't accept? Uh oh, hope they don't "fix the problem" by adding similar validation on the server side later :P
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