Hacking a password-protected .zip file

Hello,

I have a password-protected .zip file which I've lost its password during a system crash (the password was stored in a text file).
The problem is that the password (as I do remember) was a random alphanumeric string with a length of 10+ chars (can't really be exact on this but I'm pretty sure it's 10+), so a brute password hack may take months

Is there any efficient way I can crack this password?

 

I do not see any option other than bruteforce. But you could go the other way round and recover the txt file containing the password using a data recovery tool. That would be much easier than cracking a password. Do backup files regularly as it helps in data disasters.

 

Thanks for the tip but I couldn't recover that file as (apparently) it got overwritten when new OS was installed.

As to brute force hacks: what do you know about the rate (speed) of the best free brute force cracker software?

 

given that it is random there wont be much difference in speed of programs and the speed of your PC will be the key

 

Just Brute Force it (Takes average a month or so)

 

The password has to be stored in the file somewhere. If it wasn't then how would the reader know you're entering a valid password ?

If you're going to do somthing, figure out where that somewhere is & work on that.

 

But won't it be one-way encrypted?

 

I don't know.

 

The only way is brute force.

How long it takes depending on how long the actual password is.

If the password length is 5 characters, then you are looking at 94 factorial limit 5: 6,586,922,160 tries.

Peace,

 

The brute force attack does support full parallelism in this case so, if you can use 10 computers you will divide the total time by 10.

 

There is a program called ollydbg, you can use it reverse-engineer the zip file.

 

I'm trying to crack a .zip to which I forgot the password.. I know some specs though, pretty sure it was under 8 char. I'm using fcrackzip under linux and ultimate zip cracker on windows. Time consuming, yes. But worth it.

 

In Google search for unzip file password cracking, you can find a lot of methods and tools to crack passwords, free or paid.