Feb 9, 2011 10:46 AM
(This post was last modified: Apr 24, 2012 11:05 AM by nathan72389.)
Ok, this was just something i was working on last night.
I was browsing around a few forums and a few posts. it looks like everyone is always using the same base code for their file pumpers. well, although this is a good start but theres also alot of things that they are lacking. One of them is when you pump a file then stick it into an archive. your 10 meg file is now down to 30~40 KB. this is a result of simply adding a ass load of null bytes to the end of the file.
ok, knowing the "How" and "Why" i decided to explore some new stuff (well not really new, just different) on how to prevent that massive size drop when its compressed. OK, some of you may already know the solution from simply reading my previous statement. but the solution is fairly simple.. Just add some random bytes, instead of null bytes. Since its the end of the file, its not going to bother the application and will still keep its size (or close to it) when compressed, making your "Pumped" file look a little more legit.
ok, so lets see some pics..
[img]http://img819.imageshack.us/img819/5052/292011110709am.png[/img]
^^^ this is a normal pumped file what your seeing is just an ass load of null bytes at the eof.
now, when you compress this, winrar (basically) says "ok, 10 meg of nulls, drop them , add a marker , re-add them when decompressed.
now...
[img]http://img28.imageshack.us/img28/2760/292011110732am.png[/img]
^^ ok, here is all of the garbage bytes that i have added, winrar treats this just like every other crap in the file, so the compression ration is much lower for these rather than with nulls.
ok, so where does that leave us?
well, when know the problem, and we know the solution, now we just need an app to do it for us.
[img]http://img822.imageshack.us/img822/1847/62531469.gif[/img]
this was nothing more than a POC app that i was working on while figuring this all out. it does exactly what i described above.
ok, so what next?
well after doing all of the app, i quickly found out about some of the disadvantages of using this method. After having a brief conversation with a person on msn, it was suggested to simply update the win32 resources with the garbage to effectively do the same thing, but not using EOF. I didnt really want to put that much work into a POC app because, well the concept was already proven and i was happy.
so... in conclusion...
thats it, enjoy!
if your interested in the project you can download it here:
[attachment=1340]
I was browsing around a few forums and a few posts. it looks like everyone is always using the same base code for their file pumpers. well, although this is a good start but theres also alot of things that they are lacking. One of them is when you pump a file then stick it into an archive. your 10 meg file is now down to 30~40 KB. this is a result of simply adding a ass load of null bytes to the end of the file.
ok, knowing the "How" and "Why" i decided to explore some new stuff (well not really new, just different) on how to prevent that massive size drop when its compressed. OK, some of you may already know the solution from simply reading my previous statement. but the solution is fairly simple.. Just add some random bytes, instead of null bytes. Since its the end of the file, its not going to bother the application and will still keep its size (or close to it) when compressed, making your "Pumped" file look a little more legit.
ok, so lets see some pics..
[img]http://img819.imageshack.us/img819/5052/292011110709am.png[/img]
^^^ this is a normal pumped file what your seeing is just an ass load of null bytes at the eof.
now, when you compress this, winrar (basically) says "ok, 10 meg of nulls, drop them , add a marker , re-add them when decompressed.
now...
[img]http://img28.imageshack.us/img28/2760/292011110732am.png[/img]
^^ ok, here is all of the garbage bytes that i have added, winrar treats this just like every other crap in the file, so the compression ration is much lower for these rather than with nulls.
ok, so where does that leave us?
well, when know the problem, and we know the solution, now we just need an app to do it for us.
[img]http://img822.imageshack.us/img822/1847/62531469.gif[/img]
this was nothing more than a POC app that i was working on while figuring this all out. it does exactly what i described above.
ok, so what next?
well after doing all of the app, i quickly found out about some of the disadvantages of using this method. After having a brief conversation with a person on msn, it was suggested to simply update the win32 resources with the garbage to effectively do the same thing, but not using EOF. I didnt really want to put that much work into a POC app because, well the concept was already proven and i was happy.
so... in conclusion...
thats it, enjoy!
if your interested in the project you can download it here:
[attachment=1340]
