How to disassemble SWF files using freeware software or free service (Win/Mac/Linux)

[nullacht]

Flasm disassembles your entire SWF including all the timelines and events. Looking at disassembly, you learn how the Flash compiler works, which improves your ActionScript skills. You can also do some optimizations on the disassembled code by hand or adjust the code as you wish. Flasm then applies your changes to the original SWF, replacing original actions.

It's also possible to embed Flasm actions in your ActionScript, making optimizing of large projects more comfortable.

Flasm is not a decompiler. What you get is the human readable representation of SWF bytecodes, not ActionScript source. If you're looking for a decompiler, Flare may suit your needs. However, Flare can't alter the SWF.


Decompressing the .swf file using freeware command line flasm:

From HTML source code:

http://static.generation.portal.skynet.be/swf/festivalplugin-20110621.swf

Decompressing the .swf file using flasm:

flasm -x festivalplugin-20110621.swf
festivalplugin-20110621.swf successfully decompressed, 59118 bytes

Open this file with WinHex :

<settings>
	<festival id="-1" name="Location detection streamer" streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_" />
	<!-- TESTING NODE -->
	<festival id="0" name="FAKE" streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_">
		<preroll file="mp4:graspop_preroll_###lang###_###bw###.mp4" />
		<promo file="mp4:RW_Pukkelpop_QualityA.mp4" />
		<live streamer="rtmpte://live.flash.streampower.be/festivals_2k11" file="festivals_live_2k11_###bw###" />
		<vod />
	</festival>
	
	<!-- 2010 VOD CONTENT -->
	<festival id="28" name="Rock Werchter 2010" streamer="rtmpte://flash.streampower.be/festivals_2k10_pu/_definst_">
		<preroll streamer="rtmpte://flash.streampower.be/festivals_2k10_pu/_definst_" file="mp4:preroll/rock_werchter_preroll_###lang###_hi.mp4" />
		<promo />
		<live />
		<vod />
	</festival>
	<festival id="29" name="Graspop Metal Meeting 2010" streamer="rtmpte://flash.streampower.be/festivals_2k10_pu/_definst_">
		<preroll streamer="rtmpte://flash.streampower.be/festivals_2k10_pu/_definst_" file="mp4:preroll/graspop_preroll_###lang###_hi.mp4" />
		<promo />
		<live />
		<vod />
	</festival>
	<festival id="30" name="Rimpelrock 2010" streamer="rtmpte://flash.streampower.be/festivals_2k10_pu/_definst_">
		<promo />
		<live />
		<vod />
	</festival>
	<festival id="31" name="Pukkelpop 2010" streamer="rtmpte://flash.streampower.be/festivals_2k10_pu/_definst_">
		<preroll streamer="rtmpte://flash.streampower.be/festivals_2k10_pu/_definst_" file="mp4:preroll/pukkelpop_preroll_###lang###_hi.mp4" />
		<promo />
		<live />
		<vod />
	</festival>
	
	<!-- 2011 LIVE AND VOD CONTENT -->
	<festival id="36" name="Graspop Metal Meeting 2011" streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_">
		<preroll file="mp4:preroll/graspop_preroll_###lang###_###bw###.mp4" />	
		<promo file="mp4:promo/graspop_promo_###lang###_###bw###.mp4" />
		<live streamer="rtmpte://live.flash.streampower.be/festivals_2k11" file="festivals_live_2k11_###bw###" />
		<vod streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_" />
	</festival>
	<festival id="37" name="Rock Werchter 2011" streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_">
		<preroll file="mp4:preroll/rock_werchter_preroll_###lang###_###bw###.mp4" />	
		<promo file="mp4:promo/rw_pp_promo_###lang###_###bw###.mp4" />
		<live streamer="rtmpte://live.flash.streampower.be/festivals_2k11" file="festivals_live_2k11_###bw###" />
		<vod streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_" />
	</festival>
	<festival id="38" name="Pukkelpop 2011" streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_">
		<preroll file="mp4:preroll/pukkelpop_preroll_###lang###_###bw###.mp4" />	
		<promo file="mp4:promo/rw_pp_promo_###lang###_###bw###.mp4" />
		<live streamer="rtmpte://live.flash.streampower.be/festivals_2k11" file="festivals_live_2k11_###bw###" />
		<vod streamer="rtmpte://flash.streampower.be/festivals_2k11_pu/_definst_" />
	</festival>
</settings>

[mckv]

Robust ABC (ActionScript Bytecode) [Dis-]Assembler or RABCDAsm is a collection of utilities including an ActionScript 3 assembler/disassembler, and a few tools to manipulate SWF files. These are:

• rabcdasm - ABC disassembler
• rabcasm - ABC assembler
• abcexport - extracts ABC from SWF files
• abcreplace - replaces ABC in SWF files
• swfdecompress - decompresses zlib-compressed SWF files
• swf7zcompress - (re-)compress the contents of a SWF using 7-Zip
• swfbinexport / swfbinreplace - extract/replace contents of binary data tags from SWF files

How to decompile the swf with RABCDAsm (using powershell)

.\abcexport.exe .\player.swf
.\rabcdasm.exe .\player-0.abc
 cd .\player-0
 dir -recurse | select-string -pattern "secureTokenResponse"

[karlo2105]

Show My Code is a Free Online Decoder / Decompiler. It allows to decompile flash ActionScript from the swf flash file. You may use this online flash swf decompiler to get the source code of the swf file.

[svnpenn]

It should be noted that none of

* Flasm
* RabcDasm
* Flare

will decompile SWF files. Flasm and RabcDasm will disassemble swf
files into bytecode, but this is not ActionScript source code.

Flare claims to decompile but has not been updated since 2006 and does not work
on modern swf files.