Exploring
the Portable Executable
format
London, England
Ange Albertini 2013/09/13
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Workshop package
(PoCs+docs)
http://www.xchg.info/corkami/workshop.zip
Recommended PE viewer:
http://icerbero.com/peinsider
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a handmade PE
simple.exe
a first real example
working minimal
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detailed
walkthrough
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DOS header
unused in PE mode
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PE header
PE signature
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Optional Header
NOT optional in executables
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DataDirectories
end of OptionalHeader
16 (max) * [RVA, Size]
each entry interpreted differently
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Sections
memory mapping
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Imports
standard loader mechanism
NOT required
load DLL, locate APIs
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compiled PE
compiled.exe
closer to reality
extra non-critical structure
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DLL
exports
relocations
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driver
subsystem, checksum
low alignments mapping
different imports
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resources
structure
version, manifest/icon, APIs
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Thread Local Storage
callback list
before EntryPoint & after ExitProcess
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.Net
different and integrated binary
2nd loader
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what about 64b?
very few changes
● 2 magic constants
● a few elements become QWord
○ ImageBase, Imports thunks, callbacks
● Exceptions have their own DataDirectory
○ no need for LoadConfig (SafeSEH)
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and ARM
● a different magic constant
● still 16b DOS Stub !
● nothing special, PE wise
○ the beauty of ‘Portability’