Questions tagged [7zip]

7-Zip is an open source file compression and archiving application. Use this tag for questions regarding this application.

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Military-grade encryption on Blu-ray discs?

Another thread addresses the question of what can count as "military-grade encryption." In this case, I see that CyberLink Power2Go software boasts "advanced military-grade 256-bit ...
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10 votes
1 answer
3k views

Does 7-Zip really run multiple rounds of SHA-256 when key stretching?

Recently I was testing whether I could make 7-Zip archives more bruteforce-resistant. Both someone on Wikipedia and @kelalaka on this website make the following claim: The 7z format supports ...
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Application to archive a file with multiple passwords [duplicate]

Is there an application to create an archive (e.g. 7z, zip, rar, etc) that can be accessed with multiple valid passwords? For example the password protected archive "example.7z" can be ...
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2 votes
1 answer
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AES256 - 7zip Vs GPG

I noticed that 7zip provides an option to encrypt the contents of a folder using AES256 (Screenshot Below) and so does GPG using this command: gpgtar --output <Name_Of_The_Output_File> -v --...
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1 answer
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Cracking Lost Password for encrypted 7z file with most characters known

I forgot password to 7z archive encrypted with AES 256. I am fairly certain of most characters however. I know password length is either 8 or 12 characters and if it is 12 I know the last 4 characters....
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7z "Copy 7zAES" algo brute force with 32 char password for when original file is available (QNAP QLocker ransomware) [duplicate]

As some in here might know, there is/was a ransomware attack going on worldwide that used 7z to encrypt all files <20MB for a ton of users world wide. Each user has a unique 32 char password (Upper ...
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1 answer
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Is checking zip content on another PC enough to prevent data leak?

Let's say I have two kind of files on my Windows desktop - first are files that can be published and shared with other people, second kind is confidential and should remain private. To share files I ...
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1 answer
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Can I consider files compressed with password safe at all?

A follow up to my 7,5 years old question. Back 10-15 years ago, when I wanted to send an executable file over Gmail from my PC, all I had to do was to change file's extension to some meaningless one ...
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4 votes
4 answers
7k views

Are files encrypted with 7ZIP vulnerable to password crackers?

A client says they can't accept password-protected PDFs to put in their payroll system, so I have to send them without security. I don't want to send unsecured PDFs via e-mail because e-mail is ...
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  • 1,907
1 vote
3 answers
384 views

Does compression level influence security of encryted 7z files?

I want to archive some GB of sensitive data. It is to be stored on an external drive that also includes non sensitive data so i don't want to encrypt the whole drive. For that purpose i want to use ...
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2 votes
0 answers
2k views

Recovered a 7z password with hashcat, but it's not the right one

I am trying to recover a 7z file, but have forgotten the password. It's completely AES-256 encrypted (i.e. not even the filenames are available). Steps: Generated hash file with 7z2hashcat.pl Ran a ...
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2 votes
1 answer
5k views

Decrypting a password-protected 7z file with Delta filter fails

I have made a 7z archive using Delta filter containing a wav file and I have protected it with a password. I am running a terminal in Kali Linux. My problem is that I cannot get the password cracked ...
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1k views

Getting an error when running John The Ripper on 7zip file

I've never really worked with this tool, John Jumbo 1.9. I'm just curious since people say 7zip is a secure way of encrypting files, so I wanted to try it myself. Anyways, I encrypted a file with 7z, ...
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1 vote
1 answer
220 views

JohnTheRipper Advanced Mask

I have problem to construct advanced mask to crack hash of 7zip file. The password have 16 chars where are all lower, upper, decimal and !@#$%-_=+: Main information is that any char can't duplicate ...
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2 answers
1k views

Can a PowerShell script inside a Zip file execute automatically upon unzipping?

I have a zip file that has a Powershell script inside that I want to look at. Is it possible that the Powershell script could execute automatically just by unzipping the file? This is not something I ...
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How to make 7-zip files more secure? [duplicate]

I came across these articles which imply (to me) that 7-Zip's AES implementation is not good: https://twitter.com/3lbios/status/1087848040583626753 https://threadreaderapp.com/thread/...
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1 answer
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Executing vs Extracting PE32/PE32+ executable

If you have a malicious upon execution ("running" it / double clicking on it) .exe , would extracting its contents with something like 7-Zip utility mitigate its effects? Or can it still do harm?
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5 votes
1 answer
4k views

Encryption Using 7z or Zip File

I'm wondering which encrypted 7-Zip file format has better encryption: 7z with 256 AES or zip file with 256 AES? Assume that a strong password is used, then which encrypted 7zip file format has ...
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17 votes
2 answers
3k views

What is the impact of the reported weak IV in 7 Zip?

It has been reported that 7 Zip generates IVs in a weak manner. What is the actual impact of this? I'm asking about historical Zip files that I've sent. I've no plans to use 7 Zip going forward until ...
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