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rar file password recovery but rar file parts (sequential) having the same extensions and winrar gets them default.

Posted on 2009-12-30
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Last Modified: 2013-12-01
Hi there;

I have some rar files which are in sequence, winrar gets them by default and after right clicking the first file having r00, winrar starts extracting and in the end prompts for a password, I have no information of the password. Could you name a program that recovers such a  password.

I mean, as you get it, I am not trying to recover a password of a single rar file but password of a resutltant extracted folder.

Best regards.
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Question by:jazzIIIlove
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by:
Jackie Man earned 2000 total points
ID: 26147487
Unless the password is short and simple which can be attacked by brute-force approach, it is nearly impossible to recover a password of a RAR file no matter that it is a single file or a sequence of .r00, .r01... files.

For a sequence of .r00, .r01... files, the password is asked at the end of extraction. So, you are not cracking password of a resultant extracted folder.

For any kind of rar password recovery, I will suggest that you shall try Advanced RAR Password Recovery from www.elcomsoft.com/arpr.html , but it is not free and it takes many hours even days to crack a password with medium length even with a super fast computer.

Besides, as RAR file can accept non-English character for setting password (such as Chinese character), using any kind of RAR password recovery software will not help in such situation.
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Expert Comment

by:hello_everybody
ID: 26148063
Their are many different programs out there claiming to crack rar passwords, but from experience its a lost cause like mentioned by jakieman.
The most effective method I've found so far is google'ing  the file name, many times one of the results (given that its a common file) will be posted with the password.
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Author Comment

by:jazzIIIlove
ID: 26148216
Hi there;

jackieman:
>>For a sequence of .r00, .r01... files, the password is asked at the end of extraction. So, you are not >>cracking password of a resultant extracted folder.
Unfortunately, you are right.

>>For any kind of rar password recovery, I will suggest that you shall try Advanced RAR Password >>Recovery from www.elcomsoft.com/arpr.html , but it is not free and it takes many hours even days >>to crack a password with medium length even with a super fast computer.
I have that program and yes, it takes hours and no result with my 8 GB Quad.

hello_everybody:
>>The most effective method I've found so far is google'ing  the file name, many times one of the results >>(given that its a common file) will be posted with the password.
I had already do that but the file is not public and I cannot reach the owner of the file.

Let's wait for other experts to join. I need a free/paid program that ease my problem.

Best regards.
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LVL 52

Assisted Solution

by:Jackie Man
Jackie Man earned 2000 total points
ID: 26151402
It seems that RAR password recovery is a very difficult task. See the link below.

http://www.experts-exchange.com/Software/Misc/Q_21903179.html

When you open the first .r00 file, do you see the content inside? Besides, can you find out which version of  WinRAR is used to encrypt the file? (Right-click .r00 file -> select Properties)
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Author Comment

by:jazzIIIlove
ID: 26158586
>>When you open the first .r00 file, do you see the content inside?
nope.
can you find out which version of  WinRAR is used to encrypt the file
yes, 2.9.
The link you have given is a very disappointing for me:(
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Assisted Solution

by:Jackie Man
Jackie Man earned 2000 total points
ID: 26163120
Sorry, the password cannot be easily removed as WinRAR Version 2.9 upgraded the encryption algorithm to AES. It is not easy to decrypt AES.

Source: http://www.versiondownload.com/winrar/2.8.0
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Author Comment

by:jazzIIIlove
ID: 26166322
so, is it over?
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Assisted Solution

by:Jackie Man
Jackie Man earned 2000 total points
ID: 26166376
Yes. Unless you know whether the owner of the file will use what kind of password ( dictionary, a combination of character and number (how many characters)... etc.).

For examples, I will encrypt files of a user with their initial + a meaningful number (maybe a date of creating the archive or date of birth).

Besides, there maybe password stored in text file or word file which may be stored on the computer where the rar files are located.
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Assisted Solution

by:Jackie Man
Jackie Man earned 2000 total points
ID: 26166428
I think that you know how WinRAR (version 2.9 or above) encrypts and decrypt files.

In compressing files with a password, WinRAR will compress the files into a stream of data and use AES to encrypt the stream of data and put a CRC record (128 bit, i.e. 16 numbers) regarding the data length and attribute of the data (i.e. date and time).

In decompressing files, WinRAR will decompress the RAR or sequence of RAR files into a stream of data (which carries no meaning). Afterwards, WinRAR will ask the user to input password. If password is not correct, the decryption will not start as CRC record is different from the original CRC record. Besides, it is not possible to retrieve the CRC record from the RAR file as CRC record is not stored in the file header and is using an AES algorithm to embed into the stream of data.
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Author Comment

by:jazzIIIlove
ID: 26166824
>>use AES to encrypt the stream of data and put a CRC record
CRC record is also AES encrypted?
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