UPX – Ultimate Packer for Executables
upx.github.io
UPX – Ultimate Packer for Executables
1–10 of 82 posts
Re: UPX – Ultimate Packer for Executables
#2Surprised this still exists.
A little walk down memory lane: I once ran the exe mailing list for exe packers and protection tools. There was a whole scene of people in the 90s writing such tools and writing unpackers and removal tools for such things. UPX was one of the later ones that still existed when most of this scene vanished.
Re: UPX – Ultimate Packer for Executables
#3Surprised this still exists. A little walk down memory lane: I once ran the exe mailing list for exe packers and protection tools. There was a whole scene of people in the 90s writing such tools and writing unpackers and removal tools for such things. UPX was one of the later ones that still existed when most of this scene vanished.
Exists and maintained. They even keep adding support for more formats. That's pretty amazing after almost 20 years.
Re: UPX – Ultimate Packer for Executables
#4Surprised this still exists. A little walk down memory lane: I once ran the exe mailing list for exe packers and protection tools. There was a whole scene of people in the 90s writing such tools and writing unpackers and removal tools for such things. UPX was one of the later ones that still existed when most of this scene vanished.
I think some of that still exists, but the goal is to to evade anti-virus instead of compressing and deterring RE:
Re: UPX – Ultimate Packer for Executables
#5Surprised this still exists. A little walk down memory lane: I once ran the exe mailing list for exe packers and protection tools. There was a whole scene of people in the 90s writing such tools and writing unpackers and removal tools for such things. UPX was one of the later ones that still existed when most of this scene vanished.
Modern DRMs and protectors are based on the same concept(s)/protector(s) as the exes packers from the nineties.
Re: UPX – Ultimate Packer for Executables
#6Surprised this still exists. A little walk down memory lane: I once ran the exe mailing list for exe packers and protection tools. There was a whole scene of people in the 90s writing such tools and writing unpackers and removal tools for such things. UPX was one of the later ones that still existed when most of this scene vanished.
Exists and maintained . They even keep adding support for more formats. That's pretty amazing after almost 20 years.
I use it for static binaries I use where I don't care about startup times being slower.
You'd be suprised at how much of an elf binary is all 0's.
Re: UPX – Ultimate Packer for Executables
#7Earlier quoted context omitted.
Exists and maintained . They even keep adding support for more formats. That's pretty amazing after almost 20 years.
I use it for static binaries I use where I don't care about startup times being slower. You'd be suprised at how much of an elf binary is all 0's.
How large are those binaries?
I would be surprised to see practical performance degradation in uncompressing executable code before jumping to the program on today's machine. The largest binary in my /usr/bin/ is 50 megabytes. On the other hand, for very, very large binaries it's probably faster to decompress in memory rather than load all the bits from disk.
Further, most executables aren't static these days. (I often wish they were, though!). What type of binaries have you got, and are they really so big that it's worth the hassle to compress them just to save disk space?
Just interested.
Re: UPX – Ultimate Packer for Executables
#8Earlier quoted context omitted.
I use it for static binaries I use where I don't care about startup times being slower. You'd be suprised at how much of an elf binary is all 0's.
How large are those binaries? I would be surprised to see practical performance degradation in uncompressing executable code before jumping to the program on today's machine. The largest binary in my /usr/bin/ is 50 megabytes. On the other hand, for very, very large binaries it's probably faster to decompress in memory rather than load all the bits from disk. Further, most executables aren't static these days. (I oft…
50MiB to 6MiB
The binaries are mostly stuff like pandoc and compiled statically so that I can run them anywhere. Nothing too special.
Its not technically needed, but it makes network transfer faster and in general thats good enough. Its not really intended to reduce disk space really, just more a way to make things more manageable.
Re: UPX – Ultimate Packer for Executables
#9I used it to compress a Lazarus (open source Delphi clone) executable. The results were great (executable size reduced by more than 50%, iirc from 2 mb to around 800 kB).
Offering a sub MB executable in the era of 100 MB electron apps is totally pioneer :)
Re: UPX – Ultimate Packer for Executables
#10Surprised this still exists. A little walk down memory lane: I once ran the exe mailing list for exe packers and protection tools. There was a whole scene of people in the 90s writing such tools and writing unpackers and removal tools for such things. UPX was one of the later ones that still existed when most of this scene vanished.
I think some of that still exists, but the goal is to to evade anti-virus instead of compressing and deterring RE: https://hackforums.net/forumdisplay.php?fid=299
Yes, this was my first experience with this piece of software. You can pretty clearly tell that it is from UPX by examining the file in a hex editor.
I still have the malicious file on VM for me to do some analysis on it later. (if anyone would like it, feel free to contact me) edit: added the contact me