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what is meant by "brute Force" in regard...

by GeorgeCant2010 / August 13, 2010 3:46 AM PDT

to attempts by an computer to attack another computer? I think it has something to do with firewalls?

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Like a Dictionary Attack and others
by WildClay / August 13, 2010 6:31 AM PDT

Usually a "brute force" attack is one where someone is not attempting to do anything very slick, they are doing say a disctionary word attack for password, which means they just cycle through a massive list of words that would be found in a dictionary, but it is not limited, also common known dumb passwords are generally in the list.

Many other brute forces attacks look too much like a denial of service attack and are usually followed by more sophisticated attacks, like you might get a brute force or DOS on one entry point with the hacker hoping that it will get everyone attention on that, then they do the real attack on a different entry point.

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Let me add a simple brute force method.
by R. Proffitt Forum moderator / August 13, 2010 6:42 AM PDT

Years ago our IT staffer prided themselves on how locked down the machines were. Letting them finish their announcement I popped in a CD and booted up Linux and had free access to the machine's hard drive and files.

They were caught unaware that such was possible.

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Generally speaking
by Jimmy Greystone / August 13, 2010 10:26 AM PDT

Generally speaking, brute force attacks are just trying every single possibility one by one, sequentially, until you find the right one.

So say I have a 7 digit password 8985782. Using a brute force method, I would start with 0000000, then 0000001, 0000002, 0000003, and so on, until I reached 9999999 or found the right password. So, it kind of makes you cringe at how insecure your ATM card is with only a 4-digit PIN. That's only 10,000 possibilities. Your average home computer could probably crack that in a day. If the bank's security staff is doing it's job, they'd spot this attack before it got too far along, and be calling the cops, but if they are asleep at the wheel... Not good.

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Odds Much Higher...
by WildClay / August 13, 2010 1:57 PM PDT
In reply to: Generally speaking

For most banks you get between 3-5 tries and after they it eats your card in an ATM or diables it and makes you call the bank. So while a 4 number-only pin is not very secure, it is not as bad as it sounds because of the attempt limits.

It is three tries at my bank, and no human intervention, the system disables the card and/or eats it on the 3rd bad try.

I have used brute force attacks on Excel files many times, and so far have enver failed to break the password, the last time I did it was stunning how fast it cracked it, I just clicked go, and boom it had it, of course the PW was a word in the dictionary but still it was hitting Excel so fast you could not see the number in the try counter.

(PS These were my Excel files I forgot the PW on they were so old...)

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Massive attack
by Willy / August 13, 2010 10:49 AM PDT

Every possible access is attempted as if using a jumble ring of keys and trying every one of them to see if they work. No real attempt to separate what maybe more logical to try first and overall just do an all out attack as quickly as possible.

tada -----Willy Happy

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Brute force attack....
by Papa Echo / August 13, 2010 12:38 PM PDT

... like using all of my abilities and equipment [& more]... and at all costs, not caring what happen to you, nor my equipment[nor myself] achieve my objective.

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so does this have something to do with firewalls?
by GeorgeCant2010 / August 14, 2010 4:30 AM PDT
In reply to: Brute force attack....

Like if I read that and IP address is know to attempt to use brute force, whould it mean they were trying to breal through my firewall?

Or is "brute force" technique not related to attempts to get past the average home PC firewall protection?

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Not usually related by can be
by WildClay / August 14, 2010 8:18 AM PDT

I guess a port scan could be considered a form of a brute force attack, trying every port to see if you have an unproteted process/listener on the port the hacker can use to gain access, but this to me goes a little beyond what I think in brute force attacks.

It is like I an a few have described, you pick some approach and just let it rip until you break in, give up, or the other systems cuts you off.

Brute force attack are most commonly used in the context of breaking a password to gain access to an on-line account or protected machine or file. It is also used in the crypto world to mean again, just trying every possible combination using massive super-computers that are not really breaking the encryption algorithm but busting that particular encripted data they are working on. That is also called a brute force method.

However, as I said, the most common use is in breaking passwords which is why for virtually anything material these days have attempt limits set, many will also not take any word in the dictionary or repearing patterns to get the length required. Hackers found the easiest way break in is through the front door, so now we have better doors Happy

We had some much trouble with our sales guys in the field blowing their 3 shots (corporate policy is 3 tries and Info Secruity has to reset it for you, which can't be done if you are on the road.)

So now on our portables we get 10 tries, the first 3 go real fast, the 4th takes like 5 minutes before you get the prompt again, 5th is about the same, by 9 you are waiting close to an hour, this we find is enough incentive to get them to call for support before the laptop is locked out..

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so as long as the firewall blocks an attempt...
by GeorgeCant2010 / August 14, 2010 10:26 AM PDT

time and repetative attempts (using the same method) will not "wear down" the firewall?

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It Depends
by WildClay / August 14, 2010 11:32 AM PDT

First we'll take properly managed professional Firewalls as used by most major corps, like Cisco, Checkpoint, etc.

The firewall rules would be set to instantly see a port scan and the rule would likely just toss the requests, block the IP, and raise an alert if it happened enough, it would never get the chance to work.

On consumer hardware firewalls like Linksys/Cisco and others, again it varies, if you turn on remote access, and leave all defaults or a really crummy password then it could get best as few consumers would know how to set up the right rules and if they did, they would have never left the defaults or picked a weak password. (Mine is very long, and pretty much random, I don't need to access my router control panel often, so the length and complexity don't really matter but it would be nearly impossible to break by brute force.

Given that most hardware router/firewalls I know of for consumers now have most or all of the really dangerous stuff blocked and force strong passwords and you to chance othe defaults, they are getting harder and harder to brute force break.

Software firewalls like ZoneAlarm and others, are a mixed back, they can't even start the fight until the bad guy is in the front door, past the NIC and through the stack, and I can't speak for their rule sophistication since I use a hardware firewall as my primary defence follewed with Norton Internet Security and and MS Defender. However, there is really no brute force access points on these, a hackers is going to be using tools to use exploits found in the software which is not generally considered brute force.

Finally on the commercial side, most, like my shop also has very sophisiticated intrusion detection as well as firewalls, the intrusion detection software, somewhat like virus protection software has a lot know known attack patterns in its database and it is constantly scanning the traffic for not only break in attempts but even data theft. For example, if it detects what looks like an account number, it will automatically X out all but the last 4 characters, if it sees more than a specific number of what looks like account number flowing out, it cuts them off.

On the intrusion side, it looks for not only most known attacks, but it is pseudo-AI and if it see patterns that hit a certain level of "out of the norm" traffic, it will raise alerts to Info Security, if it is bad enough it will cut it off.

So that was a lot of words to say, no, repeated attempts of the same method will not "wear down" any firewall I am aware of, does not mean it can't on some, but none I have heard of.

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Brute force.....doing much more than is necessary...
by Papa Echo / August 15, 2010 12:05 AM PDT

... I like to think along the lines of ...if you cannot crack a nut with your fingers, doi t with a hammer...or if a robber comes to you with a knife, blast the person off with an M16... As for your firewall, if you cannot kick it down with your foot, there is a rocket launcher.....

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