added yara (#10901)

var/spack/repos/builtin/packages/yara/package.py

+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Yara(AutotoolsPackage):
+    """YARA is a tool aimed at (but not limited to) helping malware researchers
+    to identify and classify malware samples"""
+
+    homepage = "http://virustotal.github.io/yara/"
+    url      = "https://github.com/VirusTotal/yara/archive/v3.9.0.tar.gz"
+
+    version('3.9.0', sha256='ebe7fab0abadb90449a62afbd24e196e18b177efe71ffd8bf22df95c5386f64d')
+
+    depends_on('autoconf', type='build')
+    depends_on('automake', type='build')
+    depends_on('libtool',  type='build')
+    depends_on('m4',       type='build')