Re:Creative anti-debugger technique in Spotify for Windows
by tptacek on Tuesday May 26, 2009 @03:50PM
(#627386)
Yes. The predictable difference is timing.
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Re:Creative anti-debugger technique in Spotify for Windows
by asciilifeform on Tuesday May 26, 2009 @07:26PM
(#627707)
Hypothetically, software could be fed false outputs from timer-register reads in much the same way as it is fed false outputs from privileged instruction calls in VMWare. I am not aware of any publicly available emulator which does this, however.
Alternatively, one could use automated means to find sections of a binary which behave in a logically distinct manner (branch differently in at least one place) when emulated instruction timings are twiddled. Then turn the disassembled section red in your debugger and attack it manually.