/etc/l7-protocols/protocols/mute.pat is in l7-protocols 20090528-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 | # MUTE - P2P filesharing - http://mute-net.sourceforge.net
# Pattern attributes: marginal fast fast
# Protocol groups: p2p open_source
# Wiki: http://www.protocolinfo.org/wiki/MUTE
# Copyright (C) 2008 Matthew Strait, Ethan Sommer; See ../LICENSE
#
# This pattern is lightly tested. I don't know for sure that it will
# match the actual file transfers.
mute
^(Public|AES)Key: [0-9a-f]*\x0aEnd(Public|AES)Key\x0a$
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