FAQ - Virus?
Q: Why does my virus checker complain about the PTB-3 distribution (Windows)? I'm getting complaints about
Psychtoolbox\PsychContributed\.svn\text-base\nc111nt.zip.svn-base\nc.exe
Psychtoolbox\PsychContributed\.svn\text-base\nc.exe.svn-base
Psychtoolbox\PsychContributed\.svn\text-base\nc111nt.zip.svn-base
Psychtoolbox\PsychContributed\nc111nt.zip\nc.exe
Psychtoolbox\PsychContributed\nc111nt.zip
Psychtoolbox\PsychContributed\.svn\text-base\nc.exe.svn-base
Psychtoolbox\PsychContributed\.svn\text-base\nc111nt.zip.svn-base
Psychtoolbox\PsychContributed\nc111nt.zip\nc.exe
Psychtoolbox\PsychContributed\nc111nt.zip
A: If you see this then you use an outdated version of Psychtoolbox and should upgrade to the latest beta release. Current versions of PTB beta won't have this problem. See the historical reason for this in the old answer below.
A: These are generated by a package called NetCat. We used it in the past to implement the online registration tracking, and it was called by PsychtoolboxRegistration.m as part of each PTB download/update to transmit the registration-information string to our webserver. This was the simplest solution we could think of for robustly transmitting a string over the network, without need to implement complex network protocols for each operating system and taking care of all the extra security measures for networked software, just for this purpose. We no longer need netcat, so it isn't included any longer in PTB and the virus scanner problem shouldn't exist anymore.
Netcat is part of any standard Linux & Mac OS/X install, but not part of Windows. The nc.exe in PTB is the Windows version of netcat, and as netcat is a GPL utility, we are required to provide the source code to it. That's why the nc111nt.zip file is included.
The virus scanner is right that it could be used to gain remote access to the computer if used in a different way, but just using Matlab 7's networking functions would also allow us to do the same thing. That is, our view is that once you install MATLAB, installing NetCat isn't doing any more damage.
So the solution is simple: Either configure your virus scanner to ignore the files mentioned above - or the netcat utility, or - if you don't know how to do this - temporarily disable the virus scanner during downloads or updates of Psychtoolbox.
If a download/update attempt has failed already, you'll need to manually delete the Psychtoolbox folder from your harddisk before retrying the procedure.
