Executable compressors work by compressing selected portions of executables. At runtime, compressed executables are decompressed and reconstructed directly into their virtual image (memory) so that no data is ever written to the disk. The executable can therefore be run exactly as it was before without the user even knowing it was compressed.

PECompact2 is a next generation win32 executable/module compressor. Commonly termed an 'executable packer', such utilities compress executables and modules (i.e. *.EXE, *.DLL, *.OCX, *.SCR). At runtime the compressed modules are rapidly decompressed in memory.

Why would one want to compress an executable/module?
There are many reasons. One of the most common is that compression offers an inherent degree of tamper resistance and obfuscation. Another is that since the usual compression ratio is greater than 70% (that is, the compressed file is 30% of the original), larger executables and modules may load much quicker from the network or disk hosting them. Since storage medium is often the largest bottleneck in overall system performance, the time spent decompressing can be much less than the time saved by not having to load as much data from the storage medium.

Add tamper resistance.
Obfuscate and help deter reverse engineering.
Compression is typically 70% or greater on large files, far better than popular file compression software. This is because compression is targeted to a specific file/data format.
Load time can be improved by having a smaller image to load from the storage medium (disk, network, etc..).
But there are some other tricks that PECompact2 can do, aren't there?
Yes, PECompact2 has been built to be very extensible. Using advanced plug-ins by, PECompact2 is able to be enhanced and extended by third parties.
PECompact2 includes plug-ins to perform CRC checks, password based encryption, message box prompt for permission to execute, and much-much more. And since these plugins can all be combined in any order and quantity, each compressed file can be very unique.
For absolute uniqueness, the loader itself (decompression stub) is also a plug-in type and so can be changed or extended.

Codec Plug-ins:
LZMA - FFCE - aPLib - JCALG1 - BriefLZ
Other Codec Plug-ins:
Password Protect - MessageBox - Invert - Copy - Expand
API Hook Plug-ins:
Fast-Import - Redirect
Loader Plug-ins:
Anti-Debug - Debug - Enhanced Anti-debug - Reduced

Choosing the right executable packer can make a huge difference!
In addition to supporting more executable/modules than any other win32 executable packers, we do it tigheter than all the rest!

Homepage: www.bitsum.com